documentclass{article}
usepackage[most]{tcolorbox}
usepackage{lipsum}
begin{document}
lipsum[1]
noindentbegin{tcolorbox}[width=.475textwidth, nobeforeafter, title=box 1]
lipsum[2]
end{tcolorbox}hfill
begin{tcolorbox}[width=.475textwidth, nobeforeafter, title=box 2]
lipsum[2]
end{tcolorbox}
lipsum[1]
end{document}