Try this code:
SELECT 1 FROM testtable LIMIT 1;
You don't need to count anything.If there's no error, then the table exists.You can use INFORMATION_SCHEMA, if you want to be correct like this:
WHERE table_schema = 'yourdb'
AND table_name = 'testtable'
Otherwise, you can also use SHOW TABLES like this :
SHOW TABLES LIKE 'yourtable';
If there is a row in the resultset, table exists.