do not fail if multuple matching tokens are found

apps/explorer/lib/explorer/chain.ex

@@ -691,10 +691,10 @@ defmodule Explorer.Chain do
       )
 
     query
-    |> Repo.one()
+    |> Repo.all()
     |> case do
-      nil -> {:error, :not_found}
-      hash -> {:ok, hash}
+      [] -> {:error, :not_found}
+      hashes -> {:ok, List.first(hashes)}
     end
   end
 

apps/explorer/test/explorer/chain_test.exs

@@ -869,6 +869,15 @@ defmodule Explorer.ChainTest do
 
       assert {:ok, _} = Chain.token_contract_address_from_token_name(name)
     end
+
+    test "return only one result if multiple records are found" do
+      name = "TOKEN"
+
+      insert(:token, symbol: name)
+      insert(:token, symbol: name)
+
+      assert {:ok, _} = Chain.token_contract_address_from_token_name(name)
+    end
   end
 
   describe "find_or_insert_address_from_hash/1" do