### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
Map<String, Object> map = XContentHelper.convertToMap(BytesReference.bytes(docSource), true, XContentType.JSON).v2();
            map.put("api_key_invalidated", true);
            docSource = XContentBuilder.builder(XContentType.JSON.xContent()).map(map);
        }
        SecurityMocks.mockGetRequest(client, id, BytesReference.bytes(docSource));
        return metadata;
    }
    private AuthenticationResult<User> tryAuthenticate(ApiKeyService service, String id, String key, ApiKey.Type type) throws Exception {
        final ThreadContext threadContext = threadPool.getThreadContext();
        try (ThreadContext.StoredContext ignore = threadContext.stashContext()) {
            final String header = "ApiKey " + Base64.getEncoder().encodeToString((id + ":" + key).getBytes(StandardCharsets.UTF_8));
            threadContext.putHeader("Authorization", header);
            final PlainActionFuture<AuthenticationResult<User>> future = new PlainActionFuture<>();
            service.tryAuthenticate(threadContext, getApiKeyCredentials(id, key, type), future);
            final AuthenticationResult<User> auth = future.get();
            assertThat(auth, notNullValue());
            return auth;
        }
    }
    public void testValidateApiKey() throws Exception {
        final String apiKeyId = randomAlphaOfLength(12);
        final String apiKey = randomAlphaOfLength(16);
        Hasher hasher = getFastStoredHashAlgoForTests();
        final char[] hash = hasher.hash(new SecureString(apiKey.toCharArray()));
        ApiKeyDoc apiKeyDoc = buildApiKeyDoc(hash, -1, false);
        ApiKeyService service = createApiKeyService(Settings.EMPTY);
        PlainActionFuture<AuthenticationResult<User>> future = new PlainActionFuture<>();
        service.validateApiKeyCredentials(
            apiKeyId,
            apiKeyDoc,