We consider a quantified version of the (propositional) modal logic $\mathsf{BK}$, proposed earlier by S. P. Odintsov and H. Wansing; this version will be denoted by $\mathsf{QBK}$. Using the canonical model method, we prove the strong completeness of $\mathsf{QBK}$ with respect to a suitable possible world semantics with expanding domains. Similar results are obtained for some natural $\mathsf{QBK}$-extensions. In particular, it is proved that the extension of $\mathsf{QBK}$ with Barcan scheme is strongly complete with respect to a suitable possible world semantics with constant domains. Moreover, we define faithful embeddings (à la Gödel-McKinsey-Tarski) of the quantified versions of Nelson's constructive logics into appropriate $\mathsf{QBK}$-extensions.