diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index 3f17acc05ca7..ad6308c32162 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -2337,6 +2337,17 @@ defmodule Explorer.Chain do
     range_min = min(range_start, range_end)
     range_max = max(range_start, range_end)
 
+    # Prefix index on blocks(number)
+    # """
+    #         (
+    #           SELECT distinct b1.number
+    #           FROM generate_series((?)::integer, (?)::integer) AS b1(number)
+    #           WHERE NOT EXISTS
+    #             (SELECT 1 FROM blocks b2 WHERE b2.number=b1.number AND b2.consensus)
+    #           ORDER BY b1.number DESC
+    #         )
+    # """
+
     ordered_missing_query =
       from(b in Block,
         right_join:
@@ -2346,7 +2357,7 @@ defmodule Explorer.Chain do
               SELECT distinct b1.number
               FROM generate_series((?)::integer, (?)::integer) AS b1(number)
               WHERE NOT EXISTS
-                (SELECT 1 FROM blocks b2 WHERE b2.number=b1.number AND b2.consensus)
+                (SELECT 1 FROM blocks b2 WHERE b2.number=b1.number AND b2.epoch IS NULL)
               ORDER BY b1.number DESC
             )
             """,