A search is presented for hidden-sector bosons, $\ensuremath{\chi}$, produced in the decay ${B}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}\ensuremath{\chi}$, with ${K}^{*}(892{)}^{0}\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and $\ensuremath{\chi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. The search is performed using $pp$-collision data corresponding to $3.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the LHCb detector. No significant signal is observed in the accessible mass range $214\ensuremath{\le}m(\ensuremath{\chi})\ensuremath{\le}4350\text{ }\text{ }\mathrm{MeV}$, and upper limits are placed on the branching fraction product $\mathcal{B}\mathbf{(}{B}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}\ensuremath{\chi}\mathbf{)}\ifmmode\times\else\texttimes\fi{}\mathcal{B}(\ensuremath{\chi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ as a function of the mass and lifetime of the $\ensuremath{\chi}$ boson. These limits are of the order of $1{0}^{\ensuremath{-}9}$ for $\ensuremath{\chi}$ lifetimes less than 100 ps over most of the $m(\ensuremath{\chi})$ range, and place the most stringent constraints to date on many theories that predict the existence of additional low-mass bosons.