### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
final PlainActionFuture<Map<String, Object>> future = new PlainActionFuture<>();
        service.crossClusterApiKeyUsageStats(future);
        assertThat(future.actionGet(), anEmptyMap());
    }
    public void testCrossClusterApiKeyUsageStatsAreZerosWhenIndexDoesNotExist() {
        securityIndex = SecurityMocks.mockSecurityIndexManager(".security", false, false);
        final ApiKeyService apiKeyService = createApiKeyService();
        final PlainActionFuture<Map<String, Object>> future = new PlainActionFuture<>();
        apiKeyService.crossClusterApiKeyUsageStats(future);
        assertThat(future.actionGet(), equalTo(Map.of("total", 0, "ccs", 0, "ccr", 0, "ccs_ccr", 0)));
    }
    public void testCrossClusterApiKeyUsageFailsWhenIndexNotAvailable() {
        securityIndex = SecurityMocks.mockSecurityIndexManager(".security", true, false);
        final ElasticsearchException expectedException = new ElasticsearchException("not available");
        when(securityIndex.getUnavailableReason()).thenReturn(expectedException);
        final ApiKeyService apiKeyService = createApiKeyService();
        final PlainActionFuture<Map<String, Object>> future = new PlainActionFuture<>();
        apiKeyService.crossClusterApiKeyUsageStats(future);
        final ElasticsearchException e = expectThrows(ElasticsearchException.class, future::actionGet);
        assertThat(e, sameInstance(expectedException));
    }
    private Map<String, Object> mockKeyDocument(
        String id,
        String key,
        User user,
        @Nullable User authUser,
        boolean invalidated,
        Duration expiry,
        @Nullable List<RoleDescriptor> keyRoles,
        ApiKey.Type type