SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cff180d692460abe200e4f0a6ef7cb5525b65f539b820ec5e7d745c5a09364cb' 
  AND token = 'p0HJP/6peY087YBih8TBVe7gbiRmRzyjCWElHGdxqs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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