If you bought it new anytime after about 1930 then you can be sure it's pre-seasoned. Every "modern" manufacturer pre-seasons their cast iron cookery.
Though wax was most often used as a protective coating for unseasoned cast iron in the era when purchasing an unseasoned cast iron pan was an option, it is still often used to this day by manufacturers who pre-season their product, just to protect it from filth accumulation during shipment and storage. For that reason, a wax coating can't reliably suggest seasoning or not.
The real test will be considering its color. Unseasoned ("raw") cast iron looks exactly like you might think untreated iron SHOULD look: a shiney silver grey. More accurately, it would remain shiney silver gray for about 2 hours before being almost completely covered by a thin film of red rust it would begin to accumulate almost immediately after being exposed to the air (I've stripped down many pieces of cast iron cookery and it's been my experience that visible rusting develops on raw cast iron within minutes of exposure to air. This is, in fact, precisely what the seasoning is intended to retard). Probably every piece of cast iron cookery you've ever seen is dark black (forgetting the common exception of ceramic coatings, which are often colored blue, red, yellow, white, etc.) That dark black IS the seasoning which covers and protects the raw shiney silver iron underneath.
Short answer: If it's black, it's seasoned.
Even shorter answer: Everything is pre-seasoned.