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 (
    95726, 95727, 95728, 95729, 95730, 95731, 
    95732, 95733, 95734, 95735, 96122, 
    96124, 96125, 96126, 96127, 96128, 
    96129, 96131, 96132, 96133, 96134, 
    96135, 96136, 96137
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.82"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "8.42",
        "eval_cost": "2.40",
        "prefix_cost": "10.82",
        "data_read_per_join": "91K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (95726,95727,95728,95729,95730,95731,95732,95733,95734,95735,96122,96124,96125,96126,96127,96128,96129,96131,96132,96133,96134,96135,96136,96137)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95726
95727
95728
95729
95730
95731
95732
95733
95734
95735
96122
96124
96125
96126
96127
96128
96129
96131
96132
96133
96134
96135
96136
96137