SELECT 
  * 
FROM 
  cscart_ec_extra_product_data 
WHERE 
  product_id = 377

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "4.30"
    },
    "table": {
      "table_name": "cscart_ec_extra_product_data",
      "access_type": "ALL",
      "rows_examined_per_scan": 11,
      "rows_produced_per_join": 1,
      "filtered": "10.00",
      "cost_info": {
        "read_cost": "4.08",
        "eval_cost": "0.22",
        "prefix_cost": "4.30",
        "data_read_per_join": "44"
      },
      "used_columns": [
        "product_id",
        "maximum_adults",
        "maximum_children",
        "maximum_room_occupancy",
        "minimum_length_of_stay",
        "maximum_length_of_stay",
        "company_id",
        "blocked_date"
      ],
      "attached_condition": "(`atulecarter_march_setup`.`cscart_ec_extra_product_data`.`product_id` = 377)"
    }
  }
}