[Err] ORA-00054: the resource is busy and its receipt is set with the NOWAIT parameter, or the time has expired

Trying to clear the table (total 1500 records):

truncate TABLE EXPORT_LOG; 

And I get the message:

 [SQL] truncate TABLE EXPORT_LOG [Err] ORA-00054: ресурс занят и задано его получение с параметром NOWAIT, либо истекло время ожидания 

And if you do:

 DELETE FROM EXPORT_LOG; 

you can wait indefinitely.