SELECT 
  cscart_ult_product_descriptions.product_id, 
  cscart_ult_product_descriptions.short_description, 
  IF(
    cscart_ult_product_descriptions.short_description = "", 
    cscart_ult_product_descriptions.full_description, 
    ""
  ) AS full_description, 
  cscart_ult_product_descriptions.meta_keywords, 
  cscart_ult_product_descriptions.meta_description, 
  cscart_ult_product_descriptions.search_words, 
  cscart_ult_product_descriptions.promo_text 
FROM 
  cscart_ult_product_descriptions 
WHERE 
  cscart_ult_product_descriptions.product_id IN (
    421, 427, 408, 382, 418, 400, 424, 381, 
    1529, 1465, 428, 415, 391, 406, 329, 
    439, 390, 393, 394, 396
  ) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'ja'

Query time 0.00071

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "6.10"
    },
    "table": {
      "table_name": "cscart_ult_product_descriptions",
      "access_type": "ref",
      "possible_keys": [
        "PRIMARY",
        "product_id",
        "company_id"
      ],
      "key": "company_id",
      "used_key_parts": [
        "company_id"
      ],
      "key_length": "4",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 17,
      "rows_produced_per_join": 1,
      "filtered": "7.41",
      "cost_info": {
        "read_cost": "2.70",
        "eval_cost": "0.25",
        "prefix_cost": "6.10",
        "data_read_per_join": "4K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "company_id",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text"
      ],
      "attached_condition": "((`eshopuga_upgr_4122`.`cscart_ult_product_descriptions`.`product_id` in (421,427,408,382,418,400,424,381,1529,1465,428,415,391,406,329,439,390,393,394,396)) and (`eshopuga_upgr_4122`.`cscart_ult_product_descriptions`.`lang_code` = 'ja'))"
    }
  }
}