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 (
    96732, 96733, 96744, 96745, 96773, 96774, 
    97827, 97828, 98138, 98139, 98140, 
    98141, 98142, 98143, 98144, 98695, 
    98696, 98702, 98703, 98704, 98705, 
    98706, 98707, 98708, 98709, 98710, 
    98711, 98712, 98713, 98714, 98715, 
    100599, 100600, 100659, 100660, 100661, 
    100662, 100663, 100664, 101105, 101106
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00114

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.47"
    },
    "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": 41,
      "rows_produced_per_join": 41,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "14.37",
        "eval_cost": "4.10",
        "prefix_cost": "18.47",
        "data_read_per_join": "156K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (96732,96733,96744,96745,96773,96774,97827,97828,98138,98139,98140,98141,98142,98143,98144,98695,98696,98702,98703,98704,98705,98706,98707,98708,98709,98710,98711,98712,98713,98714,98715,100599,100600,100659,100660,100661,100662,100663,100664,101105,101106)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}