Finding the runtime of a task by name
With a query this simple, it's going to be hard to make any major improvements.

Firstly, you should use INNER JOIN as opposed to JOIN it makes the query much easier to understand at a glance.

I would argue that you don't need to alias job_stats or job, they are both already fairly short and are much more meaningful names than J and JS 

You should use consistent indentation and you SQL is typically written with all the keywords in uppercase like this: 

SELECT job_stats.median_runtime
FROM job_stats
INNER JOIN job
    ON job.id = job_stats.id
WHERE job.name = '%s'


Lastly, is the final statement supposed to be this:

WHERE job.name LIKE '%s'


or is it correct as is, I can not tell.