MariaDB starting with 10.4.2
----------------------------
WSREP_LAST_SEEN_GTID was added as part of Galera 4 in MariaDB 10.4.2.

Syntax
------

WSREP_LAST_SEEN_GTID()

Description
-----------

Returns the Global Transaction ID of the most recent write transaction
observed by the client.

The result can be useful to determine the transaction to provide to
WSREP_SYNC_WAIT_UPTO_GTID for waiting and unblocking purposes.

URL: https://mariadb.com/kb/en/wsrep_last_seen_gtid/