Query runs slowly, although only indexes are involved. What should I concentrate on?

kkats 2016-02-19 13:31:30

This query performs poorly. All involved indexes low fragmentation and updated statistics, however there are huge differences between actual and estimated rows in several steps.
Where should I concentrate in order to tune it?
There is a missing index recommendation but the truth is that this column is part of other indexes that are indeed used in the execution.
What bothers me is that this column is queried 7 times and 4 different indexes are used in total.