MariaDB [(none)]> select * from mysql.global_priv;

...

| %               | USER                     | {"access": 0, "plugin": "unix_socket", "authentication_string": "", "password_last_changed": 1604371611}                                        

MariaDB [(none)]> GRANT USAGE ON *.* TO `USER`@`%` IDENTIFIED VIA unix_socket;

Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> select * from mysql.global_priv;

...

| %               | USER                     | {"access": 0, "plugin": "unix_socket", "authentication_string": "", "password_last_changed": 1604378772}                                        ....