In the instance when trying open 'Active Query Index Hints', the list does not load and the following error message is displayed :
"Error MessagePart of the query on sys_query_index_hint has been ignored because of read security rules on sys_query_index_hint.active"
This behaviour is by design. Only ServiceNow Engineers can access that particular table (Maint access is required).
If you need any information about this table and what records exist, please log a case in hi.service-now.com for assistance