SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '48c728a19c13dec5e5de53922edd03b7ef56c8f027a5bcdff6314f00ca050c92' 
  AND token = 'G3CbIqiO9XE3AgwIYHVKQPg+cnBZlUQE+B5r1VgafJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}