Configuracion my.cnf

[jonk]

Tengo un vps de 756 MB garantizada, 1500 MB RAM Bustable

GenuineIntel, Intel(R) Xeon(R)CPU E5335 @ 2.00GHz
Versión: psa v8.6.0_build86080822.20 os_CentOS 4.2
OS: Linux 2.6.9-023stab046.2-enterprise

Bases de Datos Mysql :6
Versión del cliente: 4.1.20
Tablas 900

Una de las tablas es de referidos que muestra los referidos de un post (blog) del estilo

SELECT count( * ) AS dominio FROM `referer_visitLog` WHERE visitUrl LIKE '/?p=72' ORDER BY dominio DESC

la tabla tiene 428.632 registros

¿Como podria optimizar mejor el mysql?

la configuracion que tengo de my.cnf es:

[mysqld]
set-variable=local-infile=0
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

skip-bdb

query_cache_type=1
query_cache_limit=3m
query_cache_size=32m
max_connections=70
wait_timeout=15
connect_timeout=10
table_cache=900
tmp_table_size=700m
max_heap_table_size=700m
thread_cache=32
thread_cache_size=80
thread_concurrency=2
long_query_time=5
key_buffer_size=4m
sort_buffer_size=1m
read_buffer_size=3m
read_rnd_buffer_size=3m
#myisan_sort_buffer_size=30M
open_files_limit=2400

set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=1m
set-variable = innodb_log_buffer_size=2m
set-variable = innodb_thread_concurrency=2
low_priority_updates=1
#log_slow_queries=/var/log/mysqld.slow.log

[mysql.server]
user=mysql
basedir=/var/lib

[mysqld_safe]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
skip-bdb

set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=500K
set-variable = innodb_log_buffer_size=500K
set-variable = innodb_thread_concurrency=2

[isamchk]
key_buffer=48m
sort_buffer=48m
read_buffer=16m
write_buffer=16m

[myisamchk]
key_buffer=48m
sort_buffer=48m
read_buffer=16m
write_buffer=16m

gracias