### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
);
                final long last = lastEvictionCheckedAt.get();
                final long now = System.nanoTime();
                if (now - last >= EVICTION_MONITOR_INTERVAL_NANOS && lastEvictionCheckedAt.compareAndSet(last, now)) {
                    final long sum = evictionCounter.sum();
                    evictionCounter.add(-sum); 
                    if (sum >= EVICTION_WARNING_THRESHOLD) {
                        logger.warn(
                            "Possible thrashing for API key authentication cache, "
                                + "[{}] eviction due to cache size within last [{}] seconds",
                            sum,
                            EVICTION_MONITOR_INTERVAL_SECONDS
                        );
                    }
                }
            }
        };
    }
    
    LongAdder getEvictionCounter() {
        return evictionCounter;
    }
    
    AtomicLong getLastEvictionCheckedAt() {
        return lastEvictionCheckedAt;
    }
    /**
     * Returns realm name of the owner user of an API key if the effective user is an API Key.
     * If the effective user is not an API key, it just returns the source realm name.
     *