A ConstantScoreQuery is like a boosted query, but it produces the same score for every document that matches the query. The score produced is equal to the query boost. The ^= operator is used to turn any query clause into a ConstantScoreQuery.
Constant Score Query Examples:
+color:blue^=1 text:shoes (inStock:true text:heliosearch)^=100 native code faceting
Syntax rational: since boosting (multiplication) is term^value, the syntax for having a constant score can be term^=value