It's not; one means that they're in the process of closing and the other that they already finished.
No, a differnt word is used for closed - look at where the vav is.
סוֹגְרִים sogrim - present tense plural masculine of the verb to close (לִסְגֹּר) i.e the action of closing. (https://www.pealim.com/dict/1314-lisgor/)
סְגוּרִים sgurim - plural masculine of the adjective closed. i.e describes an extablished state of "closed" (https://www.pealim.com/dict/4062-sagur/)
I don't understand what this is meant to mean. We would never say do you close workout a direct object in English.
I definitely read this in English "are you about to close [for business/to the public for the day] soon?"
I think this translation is unnatural in English. It should be "Excuse me, are you closing?