Toner is usually used to balance the pH of your skin though there is hydrating, exfoliating toner too, that's another story. If your mist has some of the ingredients like Glycerin, Rosewater +witch hazel, Butyl glycol, and panthenol. You can use it as a setting spray or more I should say hydrating binder spray. It helps your makeup to look less cakey. Though it'll not serve your makeup to last long, these are only for a healthy-looking, hydrated, well-bound makeup look.
If you are searching for a fixer that will make your makeup last long you have to find a solution that has polymer dissolved in alcohol, so that when you spray, the alcohol evaporates and the polymer droplets come together to form a layer or film to hold your makeup in place and make it less water-soluble that is waterproof.