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 (
    9677, 9678, 9679, 9680, 9681, 9682, 9683, 
    9684, 9685, 9686, 9687, 9688, 9689, 
    9690, 9691, 9692, 9693, 9694, 9695, 
    9696, 9697, 9698, 9699, 9700, 9701, 
    9702, 9703, 9704, 9705, 9706, 9707, 
    9708
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00079

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 (9677,9678,9679,9680,9681,9682,9683,9684,9685,9686,9687,9688,9689,9690,9691,9692,9693,9694,9695,9696,9697,9698,9699,9700,9701,9702,9703,9704,9705,9706,9707,9708)) 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"
      ]
    }
  }
}