Nite Ize Size-1 S-Biner Dual... https://www.amazon.com/dp/B001DZNZZI?ref=ppx_pop_mob_ap_share

I just use this and keep both keys together and then attach it to my main keychain when the bike is locked. Works perfect

Add two of these:

https://www.amazon.com/gp/product/B001DZNZZI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

and you have everything you need for DIY toe ties. The carabiners don't wear out like Velcro does.