SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  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 (
    9784, 9785, 9786, 9787, 9788, 9790, 9791, 
    9792, 9795, 12561, 12560, 9683, 9685, 
    9686, 9687, 9688
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00053

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (9784,9785,9786,9787,9788,9790,9791,9792,9795,12561,12560,9683,9685,9686,9687,9688) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
9683
9685
9686
9687
9688
9784 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9785 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9786 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9787 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9788 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9790 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9791 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9792 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
9795 <p> Коллекция Фантазия </p><p><iframe width="100%" height="315" src="https://www.youtube.com/embed/aQE34Ct0KGU" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></p>
12560 <p>Внимание! При размещении заказа просим учитывать, что настройки цвето-передачи экрана индивидуальны и могут не отражать реальный оттенок товара.</p>
12561 <p>Внимание! При размещении заказа просим учитывать, что настройки цвето-передачи экрана индивидуальны и могут не отражать реальный оттенок товара.</p>