SELECT 
  q_product_descriptions.product_id, 
  q_product_descriptions.short_description, 
  IF(
    q_product_descriptions.short_description = '', 
    q_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  q_product_descriptions 
WHERE 
  q_product_descriptions.product_id IN (
    29195, 29201, 29203, 29211, 29212, 29213, 
    29215, 29216, 29223, 29225, 29227, 
    29230, 29233, 29237, 29239, 29242, 
    29243, 29244, 29251, 29252, 29257, 
    29258, 29260, 29270, 29275, 29284, 
    29286, 29288, 29289, 29290
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00075

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "72.01"
    },
    "table": {
      "table_name": "q_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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "index_condition": "((`portal`.`q_product_descriptions`.`product_id` in (29195,29201,29203,29211,29212,29213,29215,29216,29223,29225,29227,29230,29233,29237,29239,29242,29243,29244,29251,29252,29257,29258,29260,29270,29275,29284,29286,29288,29289,29290)) and (`portal`.`q_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "66.01",
        "eval_cost": "6.00",
        "prefix_cost": "72.01",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}