### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
}
        public void putIfNoInvalidationSince(String docId, ApiKeyDoc apiKeyDoc, long invalidationCount) {
            final CachedApiKeyDoc cachedApiKeyDoc = apiKeyDoc.toCachedApiKeyDoc();
            lockingAtomicCounter.compareAndRun(invalidationCount, () -> {
                docCache.put(docId, cachedApiKeyDoc);
                try {
                    roleDescriptorsBytesCache.computeIfAbsent(cachedApiKeyDoc.roleDescriptorsHash, k -> apiKeyDoc.roleDescriptorsBytes);
                    roleDescriptorsBytesCache.computeIfAbsent(
                        cachedApiKeyDoc.limitedByRoleDescriptorsHash,
                        k -> apiKeyDoc.limitedByRoleDescriptorsBytes
                    );
                } catch (ExecutionException e) {
                    throw new RuntimeException(e);
                }
            });
        }
        public void invalidate(Collection<String> docIds) {
            lockingAtomicCounter.increment();
            logger.debug("Invalidating API key doc cache with ids: [{}]", Strings.collectionToCommaDelimitedString(docIds));
            docIds.forEach(docCache::invalidate);
        }
        public void invalidateAll() {
            lockingAtomicCounter.increment();
            logger.debug("Invalidating all API key doc cache and descriptor cache");
            docCache.invalidateAll();
            roleDescriptorsBytesCache.invalidateAll();
        }
    }
}