Original query:

--
 Limit  (cost=783702.85..783703.00 rows=60 width=2678) (actual time=5907.730..5907.749 rows=60 loops=1)
   ->  Sort  (cost=783702.85..790088.10 rows=2554098 width=2678) (actual time=5907.728..5907.740 rows=60 loops=1)
         Sort Key: ttna NULLS FIRST
         Sort Method: top-N heapsort  Memory: 95kB
         ->  Seq Scan on shipments  (cost=0.00..695498.47 rows=2554098 width=2678) (actual time=0.521..4042.411 rows=2557283 loops=1)
               Filter: ((NOT is_quote) AND ((type)::text = 'TourShipment'::text))
               Rows Removed by Filter: 250035
 Planning time: 2.847 ms
 Execution time: 5907.868 ms
(9 rows)