The question in this verse is not actually a question but rather an appeal to God for quick intervention. In this prayer, David asks the Lord to rescue his soul and love from destruction at the hands of his enemies and predators. Although David's prayer is a request, it also implies a degree of certainty. It does not appear that David is asking God "if" He will be able to save him; what he is asking is when the rescue will occur. The faith he had in God was strong, but the patience he had was also eroding.
In today's world, right is considered bad, and evil is considered good, causing the people of God to cry out to the Lord in increasing concern and deepening distress. This world system and the disgusting acts of fallen men are causing us to wonder how long the Lord will be able to tolerate these evils. Many of His children are grieving as they observe the injustice occurring today in the corridors of world power and in the shadows of dark places.
It appears that believers have long cried out to the Lord for vengeance against evil and injustice. However, there is no doubt that God is still in control. Every single day represents one more day of grace when men and women are saved through faith in Christ Jesus. There will come a time when He will return to make all wrongs right and judge the world in righteousness.

Dear Heavenly Father, thank You for being in control of this world. I am confident that one day, You will establish Your rule of righteousness and vindicate those who have been unjustly accused or abused. Thank You for men like David. They have passed before us but have shown us how to trust You to take care of their souls from the ravages of this world. In the days ahead, I pray that regardless of what I face, I will trust You in all things and bring glory to You. 
In Jesus's name I pray. Amen.