QUERY PLAN
Limit (cost=43.07..43.08 rows=1 width=155)
-> Group (cost=43.07..43.08 rows=1 width=155)
Group Key: sci.id
-> Sort (cost=43.07..43.08 rows=1 width=155)
Sort Key: sci.id
-> Seq Scan on tbl_sales_contract_invoices sci (cost=0.00..43.06 rows=1 width=155)
Filter: ((cover_invoice_id IS NULL) AND (contract_id = 4055))