Wait it out.. afaik you never want to spray during lights on or day time (if outdoors) or you risk burning your plant as the water magnifies the light/sun.
That's an old-wives tale and if true, my outdoor garden plants should be covered with burn marks.
Try if for yourself, take a hose to your plants on a sunny afternoon and see what happens.
The water droplets don't maintain their spherical shape and the point of focus is not on the leaf. Water is also a fantastic heat sink; even if the droplet shape was focusing light to single point on the leaf, it wouldn't generate enough heat on the leaf surface. The only exception is that some hairy leaves can potentially "suspend" a water droplet at just the right distance above the leaf which both focuses the light on the leaf and the water can't cool the leaf since it's not making direct contact.
The primary reason to avoid watering/spraying mid-day is to minimize evaporative losses.
There may be a whole range of reasons why it's not good to water plants in the middle of the day, but is burning the plant's leaves one of them? Dr Karl investigates the physics of plants and water.
www.abc.net.au