### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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/main/java/org/elasticsearch/xpack/security/authc/ApiKeyService.java
)
            );
            if (sourceRealm.getDomain().equals(currentRealmDomain) == false) {
                return false;
            }
        } else {
            if (currentCreator.get("realm_domain") != null) {
                return false;
            }
        }
        final Map<String, Object> newMetadata = request.getMetadata();
        if (newMetadata != null) {
            if (apiKeyDoc.metadataFlattened == null) {
                return false;
            }
            final Map<String, Object> currentMetadata = XContentHelper.convertToMap(apiKeyDoc.metadataFlattened, false, XContentType.JSON)
                .v2();
            if (newMetadata.equals(currentMetadata) == false) {
                return false;
            }
        }
        final List<RoleDescriptor> newRoleDescriptors = request.getRoleDescriptors();
        if (newRoleDescriptors != null) {
            final List<RoleDescriptor> currentRoleDescriptors = parseRoleDescriptorsBytes(apiKeyId, apiKeyDoc.roleDescriptorsBytes, false);
            if (false == (newRoleDescriptors.size() == currentRoleDescriptors.size()
                && Set.copyOf(newRoleDescriptors).containsAll(currentRoleDescriptors))) {
                return false;
            }
        }
        assert userRoleDescriptors != null;