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 (
    1179, 1281, 926, 1258, 1168, 1394, 1259, 
    1865, 390, 1204, 1864, 1863
  ) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'ja'

Query time 0.00085

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_ult_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "company_id"],
      "key": "PRIMARY",
      "key_length": "13",
      "used_key_parts": ["product_id", "lang_code", "company_id"],
      "rows": 12,
      "filtered": 100,
      "index_condition": "cscart_ult_product_descriptions.company_id = 1 and cscart_ult_product_descriptions.product_id in (1179,1281,926,1258,1168,1394,1259,1865,390,1204,1864,1863) and cscart_ult_product_descriptions.lang_code = 'ja'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
390
926
1168
1179
1204
1258
1259
1281
1394
1863
1864
1865