SQLite select, how does it work (underlyingly)?

I am working with SQLite on Android.

I want to return 10 records from a 1000 records DB, based on a where clause. e.g. "select * from log where level > 5". The column "level" is not indexed. How does SQLite retrieve the data? I assume it will go thru all the records one by one and filter out invalid record, correct?

In that case, would it be faster to just use a key-value store like LevelDb?