"AutherizationEnabled" creating a lot of performance issue

Is there any way i can improve the performance on loading camunda tasks ? I have 30k tasks on mysql with AutherizationEnabled=true . When i login to camunda webapp it takes 5/6 minutes to load results, Which is very bad. Not able to figure-out how to improve the loading time. Here are the queries running while i login to camunda tasklist page.

Please Note : I can’t make AutherizationEnabled=false.

SELECT DISTINCT RES.REV,
                RES.ID,
                RES.NAME,
                RES.PARENT_TASK_ID,
                RES.DESCRIPTION,
                RES.PRIORITY,
                RES.CREATE_TIME,
                RES.OWNER,
                RES.ASSIGNEE,
                RES.DELEGATION,
                RES.EXECUTION_ID_,
                RES.PROC_INST_ID,
                RES.PROC_DEF_ID,
                RES.CASE_EXECUTION_ID,
                RES.CASE_INST_ID,
                RES.CASE_DEF_ID,
                RES.TASK_DEF_KEY,
                RES.DUE_DATE,
                RES.FOLLOW_UP_DATE,
                RES.SUSPENSION_STATE,
                RES.TENANT_ID
FROM ACT_RU_TASK RES
LEFT JOIN ACT_RE_PROCDEF PROCDEF ON RES.PROC_DEF_ID = PROCDEF.ID
LEFT JOIN
  ( SELECT A.*
   FROM ACT_RU_AUTHORIZATION A
   WHERE A.TYPE_ < 2
     AND (A.USER_ID_ IN ('jena',
                         '*')
          OR A.GROUP_ID_ IN ('camunda-admin'))
     AND ( (A.RESOURCE_TYPE = 7
            AND A.PERMS & 2 = 2
            OR A.RESOURCE_TYPE = 6
            AND A.PERMS & 64 = 64 )) ) AUTH ON (AUTH.RESOURCE_ID IN (RES.ID,
                                                                     PROCDEF.KEY_,
                                                                     '*'))
WHERE UPPER(RES.NAME_) = UPPER('Task Name1')
  AND RES.DUE_DATE_ < '2017-04-24 03:15:00'
  AND RES.DUE_DATE_ IS NOT NULL

Looks like it is a open bug from camunda.

https://app.camunda.com/jira/browse/CAM-7441

Please ask these questions in the Camunda forum.