SELECT 
  cscart_product_features.feature_id, 
  cscart_product_features.feature_type, 
  cscart_product_features_descriptions.description as name, 
  CASE WHEN (
    cscart_product_features.feature_type IN ('M', 'S', 'E')
  ) THEN GROUP_CONCAT(
    cscart_product_feature_variant_descriptions.variant
  ) ELSE CASE WHEN (
    cscart_product_features.feature_type IN ('O')
  ) THEN cscart_product_features_values.value_int ELSE cscart_product_features_values.value END END as val 
FROM 
  cscart_product_features 
  INNER JOIN cscart_product_features_descriptions ON cscart_product_features_descriptions.feature_id = cscart_product_features.feature_id 
  AND cscart_product_features_descriptions.lang_code = 'en' 
  INNER JOIN cscart_product_features_values ON cscart_product_features_values.feature_id = cscart_product_features_descriptions.feature_id 
  AND cscart_product_features_values.product_id = 39137 
  AND cscart_product_features_values.lang_code = 'en' 
  LEFT JOIN cscart_product_feature_variants ON cscart_product_feature_variants.variant_id = cscart_product_features_values.variant_id 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variants.variant_id = cscart_product_feature_variant_descriptions.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'en' 
GROUP BY 
  cscart_product_features.feature_id

Query time 0.00138

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "32.69"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "6.92"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_product_features_descriptions",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY"
            ],
            "rows_examined_per_scan": 106,
            "rows_produced_per_join": 10,
            "filtered": "10.00",
            "cost_info": {
              "read_cost": "9.79",
              "eval_cost": "1.06",
              "prefix_cost": "10.85",
              "data_read_per_join": "24K"
            },
            "used_columns": [
              "feature_id",
              "description",
              "lang_code"
            ],
            "attached_condition": "(`cscart_db`.`cscart_product_features_descriptions`.`lang_code` = 'en')"
          }
        },
        {
          "table": {
            "table_name": "cscart_product_features_values",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "lang_code",
              "product_id",
              "fpl",
              "idx_product_feature_variant_id",
              "fl"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "feature_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "cscart_db.cscart_product_features_descriptions.feature_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "50.00",
            "cost_info": {
              "read_cost": "6.27",
              "eval_cost": "0.69",
              "prefix_cost": "18.51",
              "data_read_per_join": "276"
            },
            "used_columns": [
              "feature_id",
              "product_id",
              "variant_id",
              "value",
              "value_int",
              "lang_code"
            ],
            "attached_condition": "(`cscart_db`.`cscart_product_features_values`.`lang_code` = 'en')"
          }
        },
        {
          "table": {
            "table_name": "cscart_product_features",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "feature_id"
            ],
            "key_length": "3",
            "ref": [
              "cscart_db.cscart_product_features_descriptions.feature_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.73",
              "eval_cost": "0.69",
              "prefix_cost": "20.93",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "feature_id",
              "feature_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_feature_variants",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "variant_feature_idx",
              "idx_var_feat_pos"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id"
            ],
            "key_length": "3",
            "ref": [
              "cscart_db.cscart_product_features_values.variant_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "1.73",
              "eval_cost": "0.69",
              "prefix_cost": "23.35",
              "data_read_per_join": "7K"
            },
            "used_columns": [
              "variant_id"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_feature_variant_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "cscart_db.cscart_product_feature_variants.variant_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.73",
              "eval_cost": "0.69",
              "prefix_cost": "25.77",
              "data_read_per_join": "51K"
            },
            "used_columns": [
              "variant_id",
              "variant",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}

Result

feature_id feature_type name val
31 C Express Delivery N
37 S Ingredients list Aqua, Potassium Lactate(5% Lactic Acid Buffered), Caprylic Capric Triglyceride, Helianthus Annuus Seed Oil, Glycerin, Calendula Oil, Niacinamide, Dimethicone, Butyrospermum Parkii (Shea) Butter, Cetyl Alcohol, Peg-100 Stearate, Glyceryl Stearate, Phenoxyethanol And Ethylhexylglycerin, Tocopherol Acetate, Allantoin, Disodium Edta, Xanthan Gum
62 E Brand Suganda
63 S Country of Origin India
65 M Key Ingredients Key Ingredients -5% Lactic Acid - Resurfaces dead skin -2% Niacinamide - Supports skin barrier and reduces uneven skin tone -Calendula oil - Nourishes and soothes skin
68 N Net Volume
72 T How to Use Apply immediately after bath on semi-damp skin.When to use :Use twice daily(AM + PM) for best results.
74 N Net Content
76 S Expiry or Best Before Month 18 months from manufacturing date.
130 T Length 7.3
131 T Breadth 7.3
132 T Height 19.5
143 C BBB N
154 E Featured Ingredient
155 C Test Promo N
156 C Update image Y
160 C Target Body Part N
167 M Sale Identifier NOHALFPRICE2207