A4988 with tiny (10x10mm) radiators and one 60x60x15mm fan, blowing directly on these radiators.
Do not worry. All is fine if you don't exceed 2 Amps limit on each motor. My works well at 0,75 - 1 Amps (middle position on trimpot). Motors 1.75A 45W.
PSU - from PC (450W), modified to 15 Volts 30 Amps for fast heatbed heating