SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461849c3e54fdf91fbf0f9013f0e12d806bd34c4008dcccb536d0ea7aa21cb8f' 
  AND token = 'cGHPGhmrqK4CbEdhLGhPiD1wHLXd8EKaRxKNbhkruaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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