There is no prohibition against the use of "sex toys" in the Bible. However, any intimate act involving sexuality is only condoned within the constraints of marriage. How a married couple expresses their sexual intimacy is their own business.
Here is an overriding spiritual principle:
1Thessalonians 4:3-5 God's will is for you to be holy, so stay away from all sexual sin. 4 Then each of you will control his own body and live in holiness and honour - 5 not in lustful passion like the pagans who do not know God and His ways. [New Living Translation]
Sexual expression in marriage is supposed to be an expression of love and unity NOT of worldly lust. If you are motivated by lust, then your use of such devices is sinful. Personally, I cannot see why anyone would you use such "toys" except as an expression of lust and not necessarily of loving desire. Going down that path can be dangerous. What next? Adding other people to enhance your sexual experience? Be careful of rationalization on this point. You may be able to fool yourself but God looks upon the heart and He knows your real motive.
Here are links to information on the website which you will find useful:
Marriage in the Lord part 1 www.thisisyourbible.com/library/show/241
Marriage in the Lord part 2 www.thisisyourbible.com/library/show/735
I hope you have found this helpful.