SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  cscart_product_descriptions.full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    64749, 64750, 64759, 64760, 64761, 65230, 
    65231, 65245, 65251, 65252, 65369, 
    65579, 65581, 65588, 66526, 66527, 
    66528, 66529, 66530, 66532, 66533, 
    66534, 66535, 66536
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.45"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.05",
        "eval_cost": "2.40",
        "prefix_cost": "18.45",
        "data_read_per_join": "109K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`cscart_db`.`cscart_product_descriptions`.`product_id` in (64749,64750,64759,64760,64761,65230,65231,65245,65251,65252,65369,65579,65581,65588,66526,66527,66528,66529,66530,66532,66533,66534,66535,66536)) and (`cscart_db`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}