diff --git a/schema/mysql/schema.sql b/schema/mysql/schema.sql
index 467b810de..070dab04a 100644
--- a/schema/mysql/schema.sql
+++ b/schema/mysql/schema.sql
@@ -987,7 +987,8 @@ CREATE TABLE customvar_flat (
 
   PRIMARY KEY (id),
 
-  INDEX idx_customvar_flat_customvar_id (customvar_id)
+  INDEX idx_customvar_flat_customvar_id (customvar_id),
+  INDEX idx_customvar_flat_flatname_flatvalue (flatname, flatvalue(255)) COMMENT 'Lists filtered by custom variable'
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin ROW_FORMAT=DYNAMIC;
 
 CREATE TABLE user (
diff --git a/schema/mysql/upgrades/1.2.0.sql b/schema/mysql/upgrades/1.2.0.sql
index b91f9adec..fceddaae6 100644
--- a/schema/mysql/upgrades/1.2.0.sql
+++ b/schema/mysql/upgrades/1.2.0.sql
@@ -1 +1,4 @@
 ALTER TABLE customvar_flat MODIFY COLUMN flatvalue text DEFAULT NULL;
+
+ALTER TABLE customvar_flat
+    ADD INDEX idx_customvar_flat_flatname_flatvalue (flatname, flatvalue(255)) COMMENT 'Lists filtered by custom variable';
diff --git a/schema/pgsql/schema.sql b/schema/pgsql/schema.sql
index 96f938f85..b14f39ee6 100644
--- a/schema/pgsql/schema.sql
+++ b/schema/pgsql/schema.sql
@@ -1564,6 +1564,7 @@ ALTER TABLE customvar_flat ALTER COLUMN customvar_id SET STORAGE PLAIN;
 ALTER TABLE customvar_flat ALTER COLUMN flatname_checksum SET STORAGE PLAIN;
 
 CREATE INDEX idx_customvar_flat_customvar_id ON customvar_flat(customvar_id);
+CREATE INDEX idx_customvar_flat_flatname_flatvalue ON customvar_flat(flatname, flatvalue);
 
 COMMENT ON COLUMN customvar_flat.id IS 'sha1(environment.id + flatname + flatvalue)';
 COMMENT ON COLUMN customvar_flat.environment_id IS 'environment.id';
@@ -1571,6 +1572,8 @@ COMMENT ON COLUMN customvar_flat.customvar_id IS 'sha1(customvar.id)';
 COMMENT ON COLUMN customvar_flat.flatname_checksum IS 'sha1(flatname after conversion)';
 COMMENT ON COLUMN customvar_flat.flatname IS 'Path converted with `.` and `[ ]`';
 
+COMMENT ON INDEX idx_customvar_flat_flatname_flatvalue IS 'Lists filtered by custom variable';
+
 CREATE TABLE "user" (
   id bytea20 NOT NULL,
   environment_id bytea20 NOT NULL,
diff --git a/schema/pgsql/upgrades/1.2.0.sql b/schema/pgsql/upgrades/1.2.0.sql
index abda26117..cc08b60e0 100644
--- a/schema/pgsql/upgrades/1.2.0.sql
+++ b/schema/pgsql/upgrades/1.2.0.sql
@@ -1 +1,4 @@
 ALTER TABLE customvar_flat ALTER COLUMN flatvalue DROP NOT NULL;
+
+CREATE INDEX idx_customvar_flat_flatname_flatvalue ON customvar_flat(flatname, flatvalue);
+COMMENT ON INDEX idx_customvar_flat_flatname_flatvalue IS 'Lists filtered by custom variable';