SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '736f8841e8cc7a99162246bc783d7035e211672c08f0034b2fc1793c30ef99d4' 
  AND token = 'NHlsY3TOUsKZDXNo87oLAiAu7WF+AzcawbiHOavBbNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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