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 (
    98662, 98663, 98664, 98665, 98666, 98667, 
    98668, 98669, 98670, 98671, 98672, 
    98673, 98674, 98675, 98676, 98677, 
    98678, 98679, 98680, 99683, 99684, 
    99685, 99686, 99687, 99688, 99689, 
    99690, 99691, 99692, 99693, 99694, 
    99695, 99696, 99704, 99705, 99717, 
    99718, 99720, 99832, 99833, 99834, 
    99839, 99840, 99841, 99842, 99843, 
    99844, 99845
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00094

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 (98662,98663,98664,98665,98666,98667,98668,98669,98670,98671,98672,98673,98674,98675,98676,98677,98678,98679,98680,99683,99684,99685,99686,99687,99688,99689,99690,99691,99692,99693,99694,99695,99696,99704,99705,99717,99718,99720,99832,99833,99834,99839,99840,99841,99842,99843,99844,99845)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}