SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'be52de0afd84cddd9b066287b678ba0c397ea2d37866b8e83b4921a25ccc72f8' 
  AND token = '7MJfMYODDmWr1OSsQgyE/cU9jbTSa0WDEq6xmUzAhFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}