SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df2e682ab109f80b91be10bfc064f4236fd7906809744581199cda3f6559a844' 
  AND token = '1IXNMNJmWtIwSjEkNdbVhJTq0vkEPfo4f/z8nUXjTb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}