SQL> select username,account_status
  2  from dba_users
  3  where username in ('SYS','SYSTEM','SCOTT');
 
 USERNAME                       ACCOUNT_STATUS
 ------------------------------ --------------------------------
 SCOTT                          LOCKED(TIMED)
 SYSTEM                         LOCKED(TIMED)
 SYS                            OPEN
 
SQL> -- put everything back as was
SQL> alter user scott account unlock;
 
 User altered.