SCCM Query computers inactive 45days

This is a query to find out all the Workstations that are been inactive for the last 45 days 
select 
SMS_R_SYSTEM.ResourceID,
SMS_R_SYSTEM.ResourceType,
SMS_R_SYSTEM.Name,
SMS_R_SYSTEM.SMSUniqueIdentifier,
SMS_R_SYSTEM.ResourceDomainORWorkgroup,
SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.Name in (select Name from SMS_R_System where ((DATEDIFF(day, SMS_R_SYSTEM.AgentTime, getdate()) >=45) and AgentName = "SMS_AD_SYSTEM_DISCOVERY_AGENT")) and SMS_R_System.Name in (select Name from SMS_R_System where ((DATEDIFF(day, SMS_R_SYSTEM.AgentTime, getdate()) >=45) and AgentName = "Heartbeat Discovery"))