I dont know of any database. But even if it exists..EphB2 expression in your HEK cultures will have to be verified by RT-PCR. Growth conditions and your particular batch of cells may affect the expression. SOme receptors get induced under certain conditions...so you can read about how EphB2 gets turned on/off in literature. Hope this helps!
It looks like they're trying to add this functionality to the protein atlas database, but it is still incomplete: http://www.proteinatlas.org/ENSG00000133216/cell
Baseed on their RNA results I would say it is not well-expressed in 293. The antibody companies seem to show no EphB2 in 293 cells unless they express exogenous protein: http://www.genetex.com/EphB2-antibody-GTX81348.html
Hi it looks unlikely that this particular receptor is present in HEK 293 as people have transfected this cell line with the gene for this protein on several occasions* (which implies it is not naturally present).
* such as: "Reelin induces EphB activation", Bouché et al 2013: Cell Research (2013) 23:473–490
I am unaware of a database of proteins expressed in cells although ATCC do have data on "cell line by gene mutation"