The speaker starts by imagining a future version of themselves, someone who is completely fine. In that future, they feel nothing about the person who hurt them and couldn't care less about what happened. It sounds calm and confident, almost like a list of things they wish were true.
But the last line gives the game away. "I'd love to be that okay in the present" admits that right now, they aren't. The earlier lines of indifference turn out to be a kind of daydream, a comfort they offer themselves. The title, "okay," in quotation marks, hints at the same thing: the word is being held up and doubted rather than simply claimed.
The mood is quiet and a little sad. The short, plain lines make the speaker sound tired rather than angry. Readers may notice how the poem sets up a brave front and then lets it slip, leaving the real feeling, hurt that hasn't healed yet, in the final line.