### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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 (colonIndex < 1) {
                    throw new IllegalArgumentException("invalid ApiKey value");
                }
                return new ApiKeyCredentials(
                    new String(Arrays.copyOfRange(apiKeyCredChars, 0, colonIndex)),
                    new SecureString(Arrays.copyOfRange(apiKeyCredChars, colonIndex + 1, apiKeyCredChars.length)),
                    expectedType
                );
            } finally {
                if (apiKeyCredChars != null) {
                    Arrays.fill(apiKeyCredChars, (char) 0);
                }
            }
        }
        return null;
    }
    void computeHashForApiKey(SecureString apiKey, ActionListener<char[]> listener) {
        threadPool.executor(SECURITY_CRYPTO_THREAD_POOL_NAME).execute(ActionRunnable.supply(listener, () -> hasher.hash(apiKey)));
    }
    
    protected void verifyKeyAgainstHash(String apiKeyHash, ApiKeyCredentials credentials, ActionListener<Boolean> listener) {
        threadPool.executor(SECURITY_CRYPTO_THREAD_POOL_NAME).execute(ActionRunnable.supply(listener, () -> {
            Hasher hasher = Hasher.resolveFromHash(apiKeyHash.toCharArray());
            final char[] apiKeyHashChars = apiKeyHash.toCharArray();
            try {
                return hasher.verify(credentials.getKey(), apiKeyHashChars);
            } finally {
                Arrays.fill(apiKeyHashChars, (char) 0);
            }