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 (
    66693, 66694, 66695, 67516, 67517, 67518, 
    67519, 67520, 67521, 67522, 67523, 
    67524, 67531, 67532, 67533, 67534, 
    67535, 67536, 67549, 67550, 67551, 
    67552, 67553, 8046
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.39"
    },
    "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": "15.99",
        "eval_cost": "2.40",
        "prefix_cost": "18.39",
        "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 (66693,66694,66695,67516,67517,67518,67519,67520,67521,67522,67523,67524,67531,67532,67533,67534,67535,67536,67549,67550,67551,67552,67553,8046)) and (`cscart_db`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}