The 6,828 occurrences of YHVH never appear as kurios mou (my lord) in the LXX, the Greek version of the NT which is very frequently cited by the NT.
So that in the scores of verses in which kurios (Lord God, Yahweh) is contrasted with a non-Deity superior, that non-Deity superior is called adoni, kurios mou, my lord.
The system of distinction is secure and obvious.
Yet, in desperation to maintain the notion that God is somehow speaking to another God in Psalm 110:1, Trinitarian Apologist James White found a couple of exceptions to this rule in Ps 15:2 and Ps 34:23LXX.
What he did not notice is that the so-called exceptions (exceptions do not make the rule!) occur when GOD, one Person (unlike Ps.110:1 where God speaks to another), is given a double address as Lord and God. That’s why the Greek adds a my (mou) to Lord (kyrios) to address God.
You will see at a glance that neither verse is in any way parallel to Psalm 110:1 and the scores of examples like it.
One must not compare apples with oranges.
Again, the 2 so-called exceptions in which God is called my Lord are readily explicable due to a single addressee.
For full article see: http://focusonthekingdom.org/definition.pdf