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 (527, 528, 529, 530, 586) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'ja'

Query time 0.00023

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": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 5,
      "filtered": 100,
      "index_condition": "cscart_ult_product_descriptions.product_id in (527,528,529,530,586)",
      "attached_condition": "cscart_ult_product_descriptions.company_id = 1 and cscart_ult_product_descriptions.lang_code = 'ja'"
    }
  }
}