### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
: (randomBoolean() ? oldMetadata : null);
        final Version newVersion = changeVersion
            ? randomValueOtherThan(oldVersion, () -> VersionUtils.randomVersion(random()))
            : oldVersion;
        final Authentication newAuthentication = changeCreator
            ? randomValueOtherThanMany(
                (auth -> auth.isApiKey() || auth.getEffectiveSubject().getUser().equals(oldAuthentication.getEffectiveSubject().getUser())),
                () -> AuthenticationTestHelper.builder()
                    .user(AuthenticationTestHelper.userWithRandomMetadataAndDetails("user", "role"))
                    .build(false)
            )
            : oldAuthentication;
        final String apiKeyId = randomAlphaOfLength(10);
        final BaseUpdateApiKeyRequest request = mock(BaseUpdateApiKeyRequest.class);
        when(request.getType()).thenReturn(type);
        when(request.getRoleDescriptors()).thenReturn(newKeyRoles);
        when(request.getMetadata()).thenReturn(newMetadata);
        final var service = createApiKeyService();
        final XContentBuilder builder = service.maybeBuildUpdatedDocument(
            apiKeyId,
            oldApiKeyDoc,
            newVersion,
            newAuthentication,
            request,
            newUserRoles
        );
        final boolean noop = (changeCreator || changeMetadata || changeKeyRoles || changeUserRoles || changeVersion) == false;
        if (noop) {
            assertNull(builder);
        } else {