Hello Marziya,
One can delete the time based scheduled actions manually by going to Monitor > Time based actions or also by editing the record in order to not let the records meet the criteria.
ou can deactivate a workflow rule at any time. If the rule has pending actions in the workflow queue, editing the record that triggered the rule removes the pending actions from the queue. If you don’t edit the record, the pending actions are processed even though the rule has been deactivated.