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 (
    9170, 9171, 9172, 9173, 9174, 9175, 9176, 
    9177, 9178, 9179, 9180, 9181, 9182, 
    9183, 9185, 9186, 9187, 9188, 9189, 
    9190, 9191, 9192, 9193, 9194, 9195, 
    9196, 9197, 9198, 9199, 9200, 9201, 
    9202
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00113

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "76.81"
    },
    "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": 32,
      "rows_produced_per_join": 32,
      "filtered": "100.00",
      "index_condition": "((`portal`.`q_product_descriptions`.`product_id` in (9170,9171,9172,9173,9174,9175,9176,9177,9178,9179,9180,9181,9182,9183,9185,9186,9187,9188,9189,9190,9191,9192,9193,9194,9195,9196,9197,9198,9199,9200,9201,9202)) and (`portal`.`q_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "70.41",
        "eval_cost": "6.40",
        "prefix_cost": "76.81",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}