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 (
    93584, 93585, 93586, 93587, 93588, 93589, 
    93590, 93591, 93592, 93593, 93594, 
    93595, 93596, 93597, 93598, 93599, 
    93600, 93601, 93602, 93603, 93604, 
    93605, 93606, 93607, 93608, 93609, 
    93610, 93611, 93612, 93613, 93614, 
    93615, 93616, 93617, 93618, 93619, 
    93620, 93621, 93622, 93623, 93624, 
    93625, 93626, 93627, 93628, 93629, 
    93630, 93631
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

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 (93584,93585,93586,93587,93588,93589,93590,93591,93592,93593,93594,93595,93596,93597,93598,93599,93600,93601,93602,93603,93604,93605,93606,93607,93608,93609,93610,93611,93612,93613,93614,93615,93616,93617,93618,93619,93620,93621,93622,93623,93624,93625,93626,93627,93628,93629,93630,93631)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}