Water (any liquid) boils at the moment when the partial pressure of its vapor above the surface becomes equal to atmospheric.
If we add salt to the water, we will slightly lower the partial pressure, so the water will boil later.
At the same time, adding salt to the water, we increase its density and thermal conductivity, with them the heat capacity also decreases, so for pure water the heat capacity is 4183 J × kg × deg, and for sea water 3891 J × kg × deg .
This means that less energy is needed to heat salt water, i.e. on the same heat, salt water will boil faster.
Which of the mechanisms makes the greatest contribution, I unfortunately do not know, but I am sure that the difference is not great. In everyday life, you simply will not notice it.
When a non-volatile substance dissolves in a liquid, the boiling point rises. So the salt water will boil later.
There is really one exception - if you boil very clean water in a very smooth container, it can overheat. If any object that can serve as a center for the formation of steam bubbles gets into the superheated water, it will instantly boil. But at home, this is almost impossible to achieve.