\documentclass{article}
\usepackage{threeparttable}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{xcolor}
\begin{document}
\begin{table}[!ht]
\setlength\tabcolsep{0pt}
\centering
\begin{threeparttable}
\begin{tabular}{@{\extracolsep{2ex}}*{2}{cc}}
\toprule
missing &  \\
an Int was here & an Int was here \\
\bottomrule
\end{tabular}
\end{threeparttable}
\end{table}
\end{document}