Find account status and profile settings for users.
The where clause in the example limits this to Password Life Time, just remove that to see all other settings.
Execute as sys:
select u.username ,u.account_status ,u.lock_date ,u.expiry_date ,u.profile ,p.resource_name ,p.limit ,p2.limit as limit_2 from dba_users u join dba_profiles p on p.profile = u.profile left join dba_profiles p2 on (p2.profile = p.limit and p2.resource_name = p.resource_name) where p.resource_name like 'PASSWORD_LIFE_TIME' order by u.username

Set password lifetime of a profile (in this example profile 'default') to unlimited: alter profile default limit password_life_time unlimited; commit;

And finally, to unlock a user run the following sql as SYS or SYSTEM: alter user user_name identified by some_password account unlock; commit;