Have you tried connecting using a UNIX socket instead of a TCP socket on localhost ? On such very short queries, the TCP overhead is significant.
Actually UNIX sockets are the default for psycopg2, had forgotten that. I get 7400 using UNIX sockets and 3000 using TCP (host="localhost") -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance