SELECT 
  cscart_product_descriptions.product_id, 
  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 (
    10525, 10526, 10527, 10528, 10529, 10530, 
    10531, 10532, 10533, 10534, 10535, 
    10536, 10537, 10538, 10539, 10540, 
    10541, 10524, 10543, 10544
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00049

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": 20,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (10525,10526,10527,10528,10529,10530,10531,10532,10533,10534,10535,10536,10537,10538,10539,10540,10541,10524,10543,10544) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}