SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03531d230a54a6221477792d9d5fbbfc336679ed4e5c5fa229498045fa331456' 
  AND token = 'uOymRYq37KguWVXdwkZcGo0MtApG8VejyNk3OpqDQTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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