SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    12752, 12753, 12754, 12755, 12756, 12757, 
    12758, 12759, 12760, 12761, 12762, 
    12763, 12764, 12765, 12766, 12767, 
    12768, 12769, 12770, 12771, 12772, 
    12773, 12774, 12775, 12776, 12777, 
    12778, 12779, 12780, 12781
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00076

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "30.31"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "index_condition": "((`test2_gaseus`.`cscart_product_descriptions`.`product_id` in (12752,12753,12754,12755,12756,12757,12758,12759,12760,12761,12762,12763,12764,12765,12766,12767,12768,12769,12770,12771,12772,12773,12774,12775,12776,12777,12778,12779,12780,12781)) and (`test2_gaseus`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "27.31",
        "eval_cost": "3.00",
        "prefix_cost": "30.31",
        "data_read_per_join": "136K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}