### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
docId2,
            apiKey2,
            new User("thor", "superuser"),
            null,
            false,
            Duration.ofSeconds(3600),
            null,
            type
        );
        PlainActionFuture<AuthenticationResult<User>> future2 = new PlainActionFuture<>();
        service.loadApiKeyAndValidateCredentials(threadContext, apiKeyCredentials2, future2);
        final ApiKeyService.CachedApiKeyDoc cachedApiKeyDoc2 = service.getDocCache().get(docId2);
        assertNotNull(cachedApiKeyDoc2);
        assertEquals("thor", cachedApiKeyDoc2.creator.get("principal"));
        final BytesReference roleDescriptorsBytes2 = service.getRoleDescriptorsBytesCache().get(cachedApiKeyDoc2.roleDescriptorsHash);
        assertSame(roleDescriptorsBytes, roleDescriptorsBytes2);
        final BytesReference limitedByRoleDescriptorsBytes2 = service.getRoleDescriptorsBytesCache()
            .get(cachedApiKeyDoc2.limitedByRoleDescriptorsHash);
        assertSame(limitedByRoleDescriptorsBytes, limitedByRoleDescriptorsBytes2);
        if (metadata2 == null) {
            assertNull(cachedApiKeyDoc2.metadataFlattened);
        } else {
            assertThat(cachedApiKeyDoc2.metadataFlattened, equalTo(XContentTestUtils.convertToXContent(metadata2, XContentType.JSON)));
        }
        assertThat(cachedApiKeyDoc2.type, is(type));
        
        final String docId3 = randomAlphaOfLength(16);
        final String apiKey3 = randomAlphaOfLength(16);
        ApiKeyCredentials apiKeyCredentials3 = getApiKeyCredentials(docId3, apiKey3, type);
        final List<RoleDescriptor> keyRoles = List.of(