SELECT 
  SQL_CALC_FOUND_ROWS cscart_cp_videos.*, 
  cscart_cp_video_descriptions.*, 
  cscart_cp_video_category_links.* 
FROM 
  cscart_cp_videos 
  LEFT JOIN cscart_cp_video_descriptions ON cscart_cp_videos.video_id = cscart_cp_video_descriptions.video_id 
  AND cscart_cp_video_descriptions.lang_code = 'en' 
  LEFT JOIN cscart_cp_video_category_links ON cscart_cp_videos.video_id = cscart_cp_video_category_links.video_id 
  INNER JOIN cscart_tag_links ON cscart_tag_links.object_id = cscart_cp_videos.video_id 
  AND cscart_tag_links.object_type = 'V' 
  INNER JOIN cscart_tags ON cscart_tag_links.tag_id = cscart_tags.tag_id 
WHERE 
  1 
  AND cscart_cp_videos.status = 'A' 
  AND (cscart_tags.tag = '#proteins') 
  AND cscart_tags.status = 'A' 
ORDER BY 
  cscart_cp_videos.timestamp desc

Query time 0.00118

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "6.21"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "2.19"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_tags",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "tag"
            ],
            "key": "tag",
            "used_key_parts": [
              "tag"
            ],
            "key_length": "767",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 0,
            "filtered": "10.00",
            "cost_info": {
              "read_cost": "0.81",
              "eval_cost": "0.01",
              "prefix_cost": "0.91",
              "data_read_per_join": "78"
            },
            "used_columns": [
              "tag_id",
              "tag",
              "status"
            ],
            "attached_condition": "(`cscart_db`.`cscart_tags`.`status` = 'A')"
          }
        },
        {
          "table": {
            "table_name": "cscart_tag_links",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "tag_id",
              "ids",
              "idx_tag_links_object_id"
            ],
            "key": "tag_id",
            "used_key_parts": [
              "tag_id",
              "object_type"
            ],
            "key_length": "6",
            "ref": [
              "cscart_db.cscart_tags.tag_id",
              "const"
            ],
            "rows_examined_per_scan": 32,
            "rows_produced_per_join": 3,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "0.10",
              "eval_cost": "0.33",
              "prefix_cost": "1.34",
              "data_read_per_join": "52"
            },
            "used_columns": [
              "tag_id",
              "object_type",
              "object_id"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_cp_videos",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "status_idx",
              "video_id_idx",
              "idx_cp_videos_status_userid_videoid",
              "idx_status_timestamp"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "video_id"
            ],
            "key_length": "3",
            "ref": [
              "cscart_db.cscart_tag_links.object_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "67.15",
            "index_condition": "(`cscart_db`.`cscart_tag_links`.`object_id` = `cscart_db`.`cscart_cp_videos`.`video_id`)",
            "cost_info": {
              "read_cost": "0.82",
              "eval_cost": "0.22",
              "prefix_cost": "2.48",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "video_id",
              "video_type",
              "company_id",
              "usergroup_ids",
              "position",
              "timestamp",
              "status",
              "user_id",
              "extra_params",
              "community_video_id",
              "community_url",
              "community_thumbnail",
              "community_video_url",
              "community_last_sync_timestamp"
            ],
            "attached_condition": "(`cscart_db`.`cscart_cp_videos`.`status` = 'A')"
          }
        },
        {
          "table": {
            "table_name": "cscart_cp_video_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "video_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "cscart_db.cscart_cp_videos.video_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.55",
              "eval_cost": "0.22",
              "prefix_cost": "3.25",
              "data_read_per_join": "9K"
            },
            "used_columns": [
              "video_id",
              "lang_code",
              "youtube_id",
              "video",
              "description",
              "short_description",
              "privacy",
              "like_count",
              "dislike_count",
              "comment_count",
              "meta_keywords",
              "meta_description",
              "page_title",
              "tagged_brands"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_cp_video_category_links",
            "access_type": "ref",
            "possible_keys": [
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "video_id"
            ],
            "key_length": "3",
            "ref": [
              "cscart_db.cscart_cp_videos.video_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.55",
              "eval_cost": "0.22",
              "prefix_cost": "4.02",
              "data_read_per_join": "35"
            },
            "used_columns": [
              "video_id",
              "category_id",
              "link_type",
              "position"
            ]
          }
        }
      ]
    }
  }
}