### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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 (getNumberOfRoleDescriptorsWithRestriction(userRoleDescriptors) > 0L) {
            return new IllegalArgumentException("owner user role descriptors must not include restriction");
        }
        final long numberOfRoleDescriptorsWithRestriction = getNumberOfRoleDescriptorsWithRestriction(requestRoleDescriptors);
        if (numberOfRoleDescriptorsWithRestriction > 0L) {
            
            if (transportVersion.before(WORKFLOWS_RESTRICTION_VERSION)) {
                return new IllegalArgumentException(
                    "all nodes must have transport version ["
                        + WORKFLOWS_RESTRICTION_VERSION
                        + "] or higher to support restrictions for API keys"
                );
            }
            
            if (numberOfRoleDescriptorsWithRestriction != 1L) {
                return new IllegalArgumentException("more than one role descriptor with restriction is not supported");
            }
            
            if (numberOfRoleDescriptorsWithRestriction != requestRoleDescriptors.size()) {
                return new IllegalArgumentException("combining role descriptors with and without restriction is not supported");
            }
        }
        return null;
    }
    private static long getNumberOfRoleDescriptorsWithRestriction(Collection<RoleDescriptor> roleDescriptors) {
        if (roleDescriptors == null || roleDescriptors.isEmpty()) {
            return 0L;
        }
        return roleDescriptors.stream().filter(RoleDescriptor::hasRestriction).count();