SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd15f856bd9f534f9cbb58043a92c789d33d9904709290c527b4d756f0028ca61' 
  AND token = 'OUJjYxHEGIZo7fJAs727daWBSfc/1Y7P6XVfCqFroGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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