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 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    83988, 83989, 84111, 90087, 90097, 88930, 
    90107, 91837, 92011, 92012, 92013, 
    92014, 92015, 92016, 92017, 92099, 
    92100, 92101, 92102, 92103, 92104, 
    92105, 83089, 84096, 83104, 84110, 
    90080, 83092, 92500, 84099, 86219, 
    89526, 89723, 90064, 89641, 91298, 
    83106, 91305, 84112, 89488, 89637, 
    92066, 92082, 83109, 83119, 85039, 
    91306, 91299
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00101

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (83988,83989,84111,90087,90097,88930,90107,91837,92011,92012,92013,92014,92015,92016,92017,92099,92100,92101,92102,92103,92104,92105,83089,84096,83104,84110,90080,83092,92500,84099,86219,89526,89723,90064,89641,91298,83106,91305,84112,89488,89637,92066,92082,83109,83119,85039,91306,91299)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}