If the white distant passed pawn were shifted one rank back, a very different position would arise! White wins since after eliminating the black distant passed pawn Black’s king will not be able to control the key-square b7 in time.
For all similar positions a universal rule holds:
White always wins provided his distant passed pawn has not crossed the black pawn's diagonal line of “refraction” from the c-file. In other words, in case of the blockaded pawns a3-a4, White can win only if the distant pawn has not crossed the g2-d5 diagonal ( rook's pawn always draws! ) .
If the blockaded pawns are a2-a3, White wins only if his distant passed pawn has not crossed the f2-d4 diagonal; whereas positions involving g- and h-pawns are always drawn.
The rule of the thumb is: a distant passed pawn is all the more valuable the nearer the second pawn is to its promotion square!