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 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    20673, 20947, 22253, 20168, 19430, 19431, 
    19432, 19438, 19439, 19440, 19443, 
    19444, 19445, 19760, 19761, 19814, 
    19815, 19816, 19817, 19819, 19861, 
    20674, 22462, 21341, 19934, 19138, 
    19433, 19434, 19435, 19436, 19437, 
    19441, 19442, 19759, 19818, 19932
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00091

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "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": 36,
          "filtered": 100,
          "index_condition": "cscart_product_descriptions.product_id in (20673,20947,22253,20168,19430,19431,19432,19438,19439,19440,19443,19444,19445,19760,19761,19814,19815,19816,19817,19819,19861,20674,22462,21341,19934,19138,19433,19434,19435,19436,19437,19441,19442,19759,19818,19932) and cscart_product_descriptions.lang_code = 'ru'"
        }
      }
    ]
  }
}