admin interface you have the info "last login" also shown in
the overview table.
SELECT CONCAT(first_name,last_name) as Agnet_Name ,u.login, Preferences_value as LastLogin FROM otrs.user_preferences,users u
where preferences_key like '%UserLastLoginTimestamp%'
and user_id = u.id
or
SELECT CONCAT(first_name,last_name) as Agnet_Name ,u.login, FROM_UNIXTIME(Preferences_value) as LastLogin FROM otrs.user_preferences,users u
where preferences_key like '%userlastlogin%'
and user_id = u.id