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 (
    51027, 51433, 51063, 51067, 51026, 51031, 
    51062, 51435, 51035, 51028, 51441, 
    51425, 51431, 51033, 51432, 51041, 
    51434, 51030, 51032, 51042, 51037, 
    51059, 51065, 51066, 51061, 51064, 
    51070, 51426, 51038, 51050, 51052, 
    51023
  ) 
  AND cscart_product_descriptions.lang_code = 'kk'

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "22.41"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 32,
      "rows_produced_per_join": 32,
      "filtered": "100.00",
      "index_condition": "((`test_uchur_k`.`cscart_product_descriptions`.`product_id` in (51027,51433,51063,51067,51026,51031,51062,51435,51035,51028,51441,51425,51431,51033,51432,51041,51434,51030,51032,51042,51037,51059,51065,51066,51061,51064,51070,51426,51038,51050,51052,51023)) and (`test_uchur_k`.`cscart_product_descriptions`.`lang_code` = 'kk'))",
      "cost_info": {
        "read_cost": "19.21",
        "eval_cost": "3.20",
        "prefix_cost": "22.41",
        "data_read_per_join": "146K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
51023
51026
51027
51028
51030
51031 фонарь, fonar, fenix, феникс, hl32rt, хл32рт, черный, chernyy
51032
51033
51035
51037
51038
51041
51042
51050 фонарь, fonar, armytek, армйтек, predator, предатор, pro, про, magnet, магнет, usb, усб, теплый, teplyy
51052
51059
51061
51062
51063
51064
51065
51066
51067
51070
51425
51426
51431
51432
51433
51434
51435
51441