ESP8266 detect LED flash with photoresistor Schmitt trigger?
how to reduce power consumption?
  does exist a better OAMP (instead of LM358) specifically designed for low power circuits?
  Since you are using an op amp as a comparator, a comparator is all that is needed and will save power. Search around to find a comparator that fits your needs, the following are a few examples.


The TI version of the LM358, is spec'd at 0.7ma typical/1.2ma worst case quiescent power supply current.

A LP339 quad comparator (Ti's version) is spec'd at 60ua typical, 100ua worst case. Link: http://www.ti.com/lit/ds/symlink/lp339-n.pdf

Linear Technology has a 0.3uA (typical/quiescent) single comparator, but costs quite a bit more than the LP339.
http://www.linear.com/product/LTC1540