Unlock APEX admin user (when apxchpwd.sql doesn't work)

First we need to find the Apex admin accounts user_id. We do that with the following statement.
You might have two. Mine was the second one

select user_id from APEX_040200.WWV_FLOW_FND_USER where user_name = 'ADMIN' order by last_update_date desc;

Set a new password for the Apex Admin with the user_id we selected.

update APEX_040200.WWV_FLOW_FND_USER
set web_password = 'password'
where user_name = 'ADMIN'
and user_id = 56502607595642;
commit;

Then we unlock the Admin account with this statement.

alter session set current_schema = APEX_040200;
begin
wwv_flow_security.g_security_group_id := 10;
wwv_flow_fnd_user_api.UNLOCK_ACCOUNT('ADMIN');
commit;
end;

List current active users, sessions and programs in Oracle 11g

List current users, sessions and programs
(not background processes)

SELECT username, sid, serial#, program
FROM v$session
WHERE username is NOT NULL
ORDER BY logon_time;

Remove there WHERE clause if you want to include all background processes like pmon.