Cannot Utilize Maximum CPU and Memory Usage for MySQL Good day.

I know this may be a duplicate of other questions however I have applied all the suggestions in many of the threads, but I remain with the same problem.

I have a single stored procedure working with max 3 tables. when I run the procedure, only 30% of my CPU is used and about 25% of RAM.

I am sitting with a CPU with 4 cores and 16GB RAM.

my.ini looks as follows:

[client]
port        = 3306
socket      = /tmp/mysql.sock

[mysqld]
port        = 3306
socket      = /tmp/mysql.sock
skip-external-locking
key_buffer_size = 512M
max_allowed_packet = 32M
table_open_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 128M
thread_cache_size = 16
query_cache_size= 32M
thread_concurrency = 0

log-bin=mysql-bin

binlog_format=mixed

server-id   = 1

innodb_buffer_pool_size = 12G
innodb_log_buffer_size = 256M
innodb_flush_log_at_trx_commit = 2
innodb_read_io_threads = 64
innodb_write_io_threads = 64

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash

[myisamchk]
key_buffer_size = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout


Is it the nature of the procedure called which is causing mysql to under utiize the hardware or is it my configuration?

I was running XAMPP but then realised it was 32-bit so I switched to the 64-bit version of WAMP. I use a 32-bit MySQLWorkbench to run queries.

I am using the InnoDB engine. 

Using MySQL Ver 14.14 Distrib 5.5.24 Win64 (x86).
The authors of High Performance MySQL describe part of your problem fairly succinctly (p. 234):


  MySQL can’t execute a single query in parallel on many CPUs. This is a feature offered
  by some other database servers, but not MySQL.


Running a single stored procedure will use no more than 1 of your CPU cores for executing queries, with a little extra on other cores being used by various background and worker threads, such as those performing I/O. MySQL will only really use the full power of a multi-core or multi-processor system when there are multiple queries running at once.

If you're seeing 30% of 1 core being used, that indicates a potential problem, but 1.2 cores out of 4 for a single query is quite normal.