Correction: Bulgarian is “kakvo iskash?”. “Shto” is only in the western dialects and it could even become “shto shtesh?” (що щеш?) in some of them. Otherwise, in literary Bulgarian, shto is a shortening of zashto, i.e. “why”. Respectively, (za)shtoto is “because”.
Otherwise, according to the old Turkic-theory dogmatists themselves, there are only 15 supposedly Turkic Bulgar words in the Bulgarian language, namely biser (pearl), beleg (scar), kniga (book; though according to them, that ultimately derives from Chinese), bъbrek (kidney), kumir (idol), korem (belly), siromah (poor man, begger), toyaga (staff, walking stick), chertog (palace) etc. Ironically, the Hungarians claim they have about 200 Turkic words which they surely must have borrowed from the Bulgars and no one else (/sarcasm). As for modern Bulgarian, we have lots of Turkic words, but the vast majority of them are from the Ottoman times (though I wouldn’t be surprised if some are also from the Cumans and Pechenegs in the Middle Ages, plus it would be strange if the Bulgars hadn’t borrowed any words and terms from the times they were under Hun, Avar and Gokturk dominion before OGB).