You need a low power variable scope of 1-4 or 1-6 power.

At roughly 1.5 to 2 power, the front sight will become invisible.

I’d recommend a Steiner P4xi 1-4X scope, ($640 at B&H Photo) they’re mid-priced optics and not cheap, but they’re excellent, have a lifetime warranty, and will perform well past the range you said you’ll be shooting at.

Keep in mind that inexpensive variable scopes with higher magnification ranges like 1-8 or 1-10X, are optically inferior to those with lower magnification ranges in the same price range.

Optical quality trumps magnification.

If you decide go with a low budget scope, buy one of the lower range of magnification optics.

When it comes to optical quality, accuracy/maintenance of zero, and durability, you get what you pay for.

Meopta makes excellent 1-6X variable scopes, the Optika 6 line, and they sell them at reasonable prices, about $100 less than the Steiner at B&H.

If you can afford to avoid the cheap Chinese scopes, avoid them, otherwise a Vortex low power variable is probably your best bet, but again, stick to their lower magnification range products.

Good luck.

ETA: shop around for the best price because prices vary widely among dealers.