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 (
    89739, 89725, 83946, 83947, 83948, 83949, 
    85657, 86388, 84100, 83093, 86221, 
    89727, 83098, 86385, 89738, 85655, 
    84104, 85652, 85656, 86386, 92002, 
    92090
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "9.92"
    },
    "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": 22,
      "rows_produced_per_join": 22,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "7.72",
        "eval_cost": "2.20",
        "prefix_cost": "9.92",
        "data_read_per_join": "83K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (89739,89725,83946,83947,83948,83949,85657,86388,84100,83093,86221,89727,83098,86385,89738,85655,84104,85652,85656,86386,92002,92090)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}