### Description

The [Get API key information API](https://www.elastic.co/guide/en/elasticsearch/reference/master/security-api-get-api-key.html) can currently filter the returned keys by:
 * key id/name
 * keys owned by the calling user
 * keys owned by other users, by `realm_name` and `username`

Irrespective of the filtering used, both invalidated and expired (but not yet deleted) keys will be included in the response.
In the response, keys have the `invalidated` boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.

I propose we introduce a way for the API to support retrieving:
* only valid API keys (not return invalidated keys) - using a boolean request parameter
* keys not expired before a certain timestamp - using a timestamp parameter that defaults to "now" - also note that keys' experiation date is always checked against the local node's clock
x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ApiKeyServiceTests.java
XContentHelper.createParser(
                    NamedXContentRegistry.EMPTY,
                    LoggingDeprecationHandler.INSTANCE,
                    BytesReference.bytes(keyDocSource),
                    XContentType.JSON
                )
            );
            PlainActionFuture<AuthenticationResult<User>> authenticationResultFuture = PlainActionFuture.newFuture();
            ApiKeyService.validateApiKeyTypeAndExpiration(
                apiKeyDoc,
                new ApiKeyService.ApiKeyCredentials("id", new SecureString(randomAlphaOfLength(16).toCharArray()), ApiKey.Type.REST),
                Clock.systemUTC(),
                authenticationResultFuture
            );
            AuthenticationResult<User> authenticationResult = authenticationResultFuture.get();
            if (randomBoolean()) {
                
                assert authenticationResult.getStatus() == AuthenticationResult.Status.SUCCESS;
                Map<String, Object> authenticationResultMetadata = new HashMap<>(authenticationResult.getMetadata());
                authenticationResultMetadata.remove(AuthenticationField.API_KEY_CREATOR_REALM_NAME);
                authenticationResult = AuthenticationResult.success(authenticationResult.getValue(), authenticationResultMetadata);
            }
            if (randomBoolean()) {
                
                assert authenticationResult.getStatus() == AuthenticationResult.Status.SUCCESS;
                Map<String, Object> authenticationResultMetadata = new HashMap<>(authenticationResult.getMetadata());
                authenticationResultMetadata.put(AuthenticationField.API_KEY_NAME_KEY, null);
                authenticationResult = AuthenticationResult.success(authenticationResult.getValue(), authenticationResultMetadata);
            }
            final ThreadContext threadContext = new ThreadContext(Settings.EMPTY);