Why a select statement get data from undo segment

 I have a sql like below     SELECT * FROM WIP_DISCRETE_JOBS WHERE ROWID = 'AAATxwAAXAABVrnAAU';

 

Normally, it is impossible to occur a performance issue because I select this table using rowid directly. But this sql take me more than 30 mins and still not finished.

If I select the same table using another rowid,  there is no problem.

 

I check the v$session_wait, I found the waiting event is "db file sequencial read" and the file is a undo tablespace datafile.  As my understanding, that means someone is updating or deleting the same row and have not committed or rollbacked yet. But I do not found any locks for this table in v$lock.