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 (
    98793, 98794, 98795, 98796, 98797, 98798, 
    98799, 98800, 98801, 98802, 98803, 
    98804, 98805, 98806, 98807, 98808, 
    98809, 98810, 98811, 98812, 98813, 
    98814, 98831, 98832, 98833, 98834, 
    98835, 98836, 98837, 98838, 98839, 
    98840, 98841, 98842, 98843, 98844, 
    98845, 98846, 98847, 98848, 98849, 
    98850, 98851, 98852, 98853, 98854, 
    98855, 98856
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00053

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (98793,98794,98795,98796,98797,98798,98799,98800,98801,98802,98803,98804,98805,98806,98807,98808,98809,98810,98811,98812,98813,98814,98831,98832,98833,98834,98835,98836,98837,98838,98839,98840,98841,98842,98843,98844,98845,98846,98847,98848,98849,98850,98851,98852,98853,98854,98855,98856)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}