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 (
    90702, 90706, 90648, 90687, 90629, 90700, 
    90704, 90677, 90684, 90685, 90690, 
    90691, 90626, 90627, 90632, 90633, 
    90646, 90619, 90644, 90667, 90609, 
    90674, 90675, 90680, 90681, 90616, 
    90617, 90622, 90623, 90657, 90642, 
    90664, 90665, 90670, 90671, 90606, 
    90607, 90612, 90613, 90599, 90709, 
    90711, 90654, 90655, 90660, 90661, 
    90698, 90699, 90703, 90707, 90640, 
    90641, 90649, 90683, 90689, 90625, 
    90631, 90596, 90597, 90602, 90603, 
    90708, 90710, 90682, 90688, 90624, 
    90630, 90696, 90697, 90701, 90705, 
    90673, 90679, 90638, 90639, 90647, 
    90615, 90621, 90672, 90678, 90651, 
    90686, 90614, 90620, 90628, 90694, 
    90695, 90636, 90637, 90645, 90663, 
    90669, 90605, 90611, 90662, 90668
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00221

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "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": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (90702,90706,90648,90687,90629,90700,90704,90677,90684,90685,90690,90691,90626,90627,90632,90633,90646,90619,90644,90667,90609,90674,90675,90680,90681,90616,90617,90622,90623,90657,90642,90664,90665,90670,90671,90606,90607,90612,90613,90599,90709,90711,90654,90655,90660,90661,90698,90699,90703,90707,90640,90641,90649,90683,90689,90625,90631,90596,90597,90602,90603,90708,90710,90682,90688,90624,90630,90696,90697,90701,90705,90673,90679,90638,90639,90647,90615,90621,90672,90678,90651,90686,90614,90620,90628,90694,90695,90636,90637,90645,90663,90669,90605,90611,90662,90668)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}