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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 (
    9846, 9845, 9860, 9859, 9858, 9857, 9852, 
    9861, 9862, 9847, 9863, 9856, 9855, 
    9838, 9849, 9850, 9853, 9842, 9851, 
    9854, 10263, 10264, 10265, 10266, 10267, 
    10268, 10269, 10270, 10271, 10272, 
    10273, 15943
  ) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'ru'

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}