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 (
    91604, 91605, 91606, 91607, 91608, 91609, 
    91625, 91551, 91552, 91553, 91554, 
    91555, 91556, 91557, 91558, 91559, 
    91560, 91597, 91623, 91561, 91562, 
    91563, 91564, 91565, 91566, 91567, 
    91568, 91569, 91570, 91628, 91629, 
    91630, 91631, 91632, 91633, 91634, 
    91635, 91636, 91637, 91638, 91639, 
    91640, 91641, 91642, 91643, 91644, 
    91645, 91646, 91647, 91688, 91689, 
    91690, 91691, 91692, 91693, 91694, 
    91695, 91696, 91697, 91678, 91679, 
    91680, 91681, 91682, 91683, 91684, 
    91685, 91686, 91687, 91590, 91591, 
    91592, 91593, 91594, 91595, 91596, 
    91598, 91599, 91600, 91649, 91650, 
    91651, 91652, 91653, 91654, 91655, 
    91656, 91657, 91659, 91660, 91661, 
    91662, 91663, 91664, 91665, 91666
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00173

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 (91604,91605,91606,91607,91608,91609,91625,91551,91552,91553,91554,91555,91556,91557,91558,91559,91560,91597,91623,91561,91562,91563,91564,91565,91566,91567,91568,91569,91570,91628,91629,91630,91631,91632,91633,91634,91635,91636,91637,91638,91639,91640,91641,91642,91643,91644,91645,91646,91647,91688,91689,91690,91691,91692,91693,91694,91695,91696,91697,91678,91679,91680,91681,91682,91683,91684,91685,91686,91687,91590,91591,91592,91593,91594,91595,91596,91598,91599,91600,91649,91650,91651,91652,91653,91654,91655,91656,91657,91659,91660,91661,91662,91663,91664,91665,91666)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}