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 (
    10965, 10985, 11005, 11027, 11047, 11067, 
    11089, 11111, 11133, 11153, 11173, 
    11195, 11215, 11237, 11259, 11279, 
    11299, 11320, 11813, 11819, 11825, 
    11831, 11838, 11844, 11851, 11869, 
    11887, 11909, 11929, 11936, 11940, 
    11944, 11951, 11958, 11959, 11960, 
    11961, 11962, 11963, 11964, 11965, 
    12030, 12031, 12032, 12033, 12034, 
    12035, 12036
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00111

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "57.81"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "index_condition": "((`gaseus`.`cscart_product_descriptions`.`product_id` in (10965,10985,11005,11027,11047,11067,11089,11111,11133,11153,11173,11195,11215,11237,11259,11279,11299,11320,11813,11819,11825,11831,11838,11844,11851,11869,11887,11909,11929,11936,11940,11944,11951,11958,11959,11960,11961,11962,11963,11964,11965,12030,12031,12032,12033,12034,12035,12036)) and (`gaseus`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "53.01",
        "eval_cost": "4.80",
        "prefix_cost": "57.81",
        "data_read_per_join": "219K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}