Examples of queries that return a scan count of 1 are:
A point query:
select title_id from titles where title_id = "T55522"
A range query:
select au_lname, au_fname from authors where au_lname > "Smith" and au_lname < "Smythe"
If the columns in the where clauses of these queries are indexed, the queries can use the indexes to scan the tables; otherwise, they perform table scans. In either case, they require only a single scan of the table to return the required rows.