### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
assertThat(cachedApiKeyDoc31.metadataFlattened, equalTo(XContentTestUtils.convertToXContent(metadata31, XContentType.JSON)));
        }
        assertThat(service.getRoleDescriptorsBytesCache().get(cachedApiKeyDoc31.roleDescriptorsHash), sameInstance(roleDescriptorsBytes3));
        assertThat(cachedApiKeyDoc31.type, is(ApiKey.Type.CROSS_CLUSTER));
        
        
        service.getRoleDescriptorsBytesCache().invalidateAll();
        Mockito.clearInvocations(client);
        final Map<String, Object> metadata4 = mockKeyDocument(
            docId,
            apiKey,
            new User("hulk", "superuser"),
            null,
            false,
            Duration.ofSeconds(3600),
            null,
            type
        );
        PlainActionFuture<AuthenticationResult<User>> future4 = new PlainActionFuture<>();
        service.loadApiKeyAndValidateCredentials(threadContext, getApiKeyCredentials(docId, apiKey, type), future4);
        verify(client, times(1)).get(any(GetRequest.class), anyActionListener());
        assertEquals(2, service.getRoleDescriptorsBytesCache().count());
        final AuthenticationResult<User> authResult4 = future4.get();
        assertSame(AuthenticationResult.Status.SUCCESS, authResult4.getStatus());
        assertThat(authResult4.getMetadata().get(API_KEY_TYPE_KEY), is(type.value()));
        checkAuthApiKeyMetadata(metadata4, authResult4);
        
        SecurityMocks.mockGetRequestException(client, new EsRejectedExecutionException("rejected"));
        PlainActionFuture<AuthenticationResult<User>> future5 = new PlainActionFuture<>();
        service.loadApiKeyAndValidateCredentials(threadContext, getApiKeyCredentials(docId, apiKey, type), future5);