Here is faster implementation.

$ ./python -m timeit -s "import sqlite3; con = sqlite3.connect(':memory:'); con.row_factory = sqlite3.NamedTupleRow; con.execute('create table t (a, b)')" -s "for i in range(100): con.execute('insert into t values (1, 2)')" -- "con.execute('select * from t').fetchall()"
100 loops, best of 3: 2.74 msec per loop

But it is still 3 times slower than sqlite3.Row.