DB Deadlock on taskUserAssoc clean up

SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction, query was: UPDATE `LEK_taskUserAssoc` SET `state` = ? WHERE (not usedState is null and (usedInternalSessionUniqId not in (select internalSessionUniqId from sessionMapInternalUniqId m, session s where s.modified + lifetime >= UNIX_TIMESTAMP() and s.session_id = m.session_id) or usedInternalSessionUniqId is null)) AND (state in ('edit', 'view'))

Same message occurred on DELETE statement some lines later.
Solution: table locks and select for update are not sufficient. So try catch the error and log it without interrupting the request with an exception.

#0 /usr/share/php/Zend/Db/Statement.php(303): Zend_Db_Statement_Pdo->_execute(Array)
#1 /usr/share/php/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute(Array)
#2 /usr/share/php/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('UPDATE `LEK_tas...', Array)
#3 /usr/share/php/Zend/Db/Adapter/Abstract.php(635): Zend_Db_Adapter_Pdo_Abstract->query('UPDATE `LEK_tas...', Array)
#4 /usr/share/php/Zend/Db/Table/Abstract.php(1133): Zend_Db_Adapter_Abstract->update('LEK_taskUserAss...', Array, Array)
#5 /var/www/html/portal-3.0.88/application/modules/editor/Models/TaskUserAssoc.php(306): Zend_Db_Table_Abstract->update(Array, Array)
#6 /var/www/html/portal-3.0.88/application/modules/editor/Controllers/TaskController.php(143): editor_Models_TaskUserAssoc->cleanupLocked()
#7 /usr/share/php/Zend/Controller/Action.php(516): editor_TaskController->indexAction()
#8 /var/www/html/portal-3.0.88/library/ZfExtended/Controllers/AAARestController.php(229): Zend_Controller_Action->dispatch('indexAction')
#9 /usr/share/php/Zend/Controller/Dispatcher/Standard.php(308): ZfExtended_RestController->dispatch('indexAction')
#10 /usr/share/php/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(REST_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#11 /usr/share/php/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#12 /usr/share/php/Zend/Application.php(384): Zend_Application_Bootstrap_Bootstrap->run()
#13 /var/www/html/portal-3.0.88/library/ZfExtended/BaseIndex.php(157): Zend_Application->run()
#14 /var/www/html/portal-3.0.88/public/index.php(11): ZfExtended_BaseIndex->startApplication()
#15