LM358 hot to the touch without any load
From the image I assume that the LM358 is the SOIC-8 device. I also assume that it is a real LM358. In your case it could be counterfeit, which is unfortunately common in these kind of modules.

Referring to the TI LM358 datasheet:



The parameter of interest here is the junction-to-case thermal resistance, $$R_{\Theta JC(top)}\ = 72.2 °C/W$$

This means that for every Watt dissipated by the IC, the case temperature will rise by 72.2°C above ambient. You've measured 55-57°C, which is roughly 30°C above ambient. This means the chip is dissipating about $$P_{LM358} = \frac{30°C}{72.2°C/W} = 400mW$$

Is that too much power dissipation? The datasheet gives a maximum junction temperature of 150°C. How hot is the junction? If the case is 57°C and you're dissipating 400mW, it must be roughly $$T_{junction}=57°C + 72.2°C/W * 0.4W = 86°C$$ The chip is operating well below its thermal limits.

Is it normal? That depends on how the circuit is designed. Since your unit functions properly, I would say that it is not an issue in this case.