In its own times (kairois idiois). Locative case. May be “in his own times.” See note on 1Ti 2:6. Clearly not for us to figure out.
Who is the blessed and only Potentate (ho makarios kai monos dunastēs). “The happy and alone Potentate.” Dunastēs, old word, in N.T. only here, Luk 1:52; Act 8:27 (the Eunuch). See note on 1Ti 1:11 for makarios.
The King of kings (ho basileus tōn basileuontōn). “The King of those who rule as kings.” Oriental title. So with “Lord of lords.” See note on Rev 10:6.