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 (
    18481, 18505, 18506, 18483, 18501, 18507, 
    18523, 18508, 18509, 18510, 18511, 
    18512, 18484, 18513, 18514, 18485, 
    18486, 18487, 18488, 18515, 18516, 
    18517, 18518, 18496, 18519, 18489, 
    18490, 18520, 18521, 18493, 18491, 
    18492, 18522
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00068

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": 33,
          "filtered": 100,
          "index_condition": "cscart_product_descriptions.product_id in (18481,18505,18506,18483,18501,18507,18523,18508,18509,18510,18511,18512,18484,18513,18514,18485,18486,18487,18488,18515,18516,18517,18518,18496,18519,18489,18490,18520,18521,18493,18491,18492,18522) and cscart_product_descriptions.lang_code = 'ru'"
        }
      }
    ]
  }
}