SELECT 
  product_descriptions.product_id, 
  product_descriptions.short_description, 
  IF(
    product_descriptions.short_description = '' 
    OR product_descriptions.short_description IS NULL, 
    product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  product_descriptions 
WHERE 
  product_descriptions.product_id IN (
    150, 162, 930, 620, 63284, 103597, 63973, 
    63954, 63950, 63629, 63268, 63380, 
    78853, 63982, 63977, 78855, 79030, 
    78872, 64033, 76716, 78874, 79110, 
    63432, 79026
  ) 
  AND product_descriptions.lang_code = 'en'

Query time 0.00423

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "20.02"
    },
    "table": {
      "table_name": "product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "11",
      "rows_examined_per_scan": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "17.62",
        "eval_cost": "2.40",
        "prefix_cost": "20.02",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`goimagine`.`product_descriptions`.`product_id` in (150,162,930,620,63284,103597,63973,63954,63950,63629,63268,63380,78853,63982,63977,78855,79030,78872,64033,76716,78874,79110,63432,79026)) and (`goimagine`.`product_descriptions`.`lang_code` = 'en'))"
    }
  }
}