From within Data Lab, access URLs for archive images are all of the same form, making it possible to construct the URL directly given just a filename:
name = 'c4d_150918_093321_ooi_i_v1'
base = "https://datalab.noao.edu/svc/cutout?col=&siaRef="
extn = ".fits.fz"
url = base + name + extn
It is also possible to query the exposure table directly:
url = queryClient.query('select access_url from ivoa_nsa.exposure where fileref = "%s.fits.fz" limit 1' % name).split('\n')
where 'name' would be the name of your image without the extension. The returned URL is for the entire image, if you want a particular extension or a cutout around a specific position there are parameters than can be added to the URL to do this as well.