Reviewing all new MySql queries on staging environment
These are some tools suggested by MySQL Performance blog post:
http://www.mysqlperformanceblog.com/tools/
pt-query-digest can be useful to review queries as well
It can review a slow log, saving results to the test.query_review table in a MySQL server running on host1. See --review for more on reviewing queries:

pt-query-digest --review h=host1,D=test,t=query_review /path/to/slow.log
Using Show Profiles also you can review query performance


http://dev.mysql.com/doc/refman/5.0/en/show-profiles.html

SET PROFILING = 1; 
SET profiling_history_size = 0; 
SET profiling_history_size = 15; 
&lt;Your own query&gt;; 
SHOW PROFILES; 
select state, round(sum(duration),5) as `duration (summed) in sec` from information_schema.profiling where query_id = 11 group by state order by `duration (summed) in sec` desc; 
SET PROFILING = 0; 



EXPLAIN EXTENDED [Your own query];


When EXPLAIN is used with the EXTENDED keyword, the output includes a filtered column not otherwise displayed. This column indicates the estimated percentage of table rows that will be filtered by the table condition. In addition, the statement produces extra information that can be viewed by issuing a SHOW WARNINGS statement following the EXPLAIN statement. The Message value in SHOW WARNINGS output displays how the optimizer qualifies table and column names in the SELECT statement, what the SELECT looks like after the application of rewriting and optimization rules, and possibly other notes about the optimization process.