OKLAHOMA CITY—A federal appeals court rejected a request from two Oklahoma death row inmates to temporarily halt their upcoming lethal injections. A three-judge panel of the 10th U.S. Circuit Court of Appeals in Denver denied the inmates’ motion in a ruling on Monday. The decision paves the way for the state to carry out the executions of Donald Grant, 46, on Thursday and Gilbert Postelle, 35, on Feb. 17. The two have argued that the state’s current three-drug lethal injection protocol that uses midazolam as the first drug will expose them to a constitutionally unacceptable risk of severe pain. But after a daylong hearing on that issue earlier this month, a federal judge in Oklahoma City determined the inmates were unlikely to succeed on the merits of their case and denied their request for a temporary stay of execution. The judge also determined that Grant and Postelle selected an alternative …