### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
.build(false)
        );
        final ApiKey.Type type = randomFrom(ApiKey.Type.values());
        final Set<RoleDescriptor> oldUserRoles = type == ApiKey.Type.CROSS_CLUSTER
            ? Set.of()
            : randomSet(0, 3, RoleDescriptorTests::randomRoleDescriptor);
        final List<RoleDescriptor> oldKeyRoles;
        if (type == ApiKey.Type.CROSS_CLUSTER) {
            oldKeyRoles = List.of(CrossClusterApiKeyRoleDescriptorBuilder.parse(randomCrossClusterApiKeyAccessField()).build());
        } else {
            oldKeyRoles = randomList(3, RoleDescriptorTests::randomRoleDescriptor);
        }
        final Map<String, Object> oldMetadata = ApiKeyTests.randomMetadata();
        final Version oldVersion = VersionUtils.randomVersion(random());
        final ApiKeyDoc oldApiKeyDoc = ApiKeyDoc.fromXContent(
            XContentHelper.createParser(
                XContentParserConfiguration.EMPTY,
                BytesReference.bytes(
                    ApiKeyService.newDocument(
                        hash,
                        randomAlphaOfLength(10),
                        oldAuthentication,
                        oldUserRoles,
                        Instant.now(),
                        randomBoolean() ? null : Instant.now(),
                        oldKeyRoles,
                        type,
                        oldVersion,
                        oldMetadata
                    )