SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435d6d4d80091ca6243febffb8c13c6ccecb321e5b1a3476724ca44e2de19afe' 
  AND token = 'N9mQJCgrI9p9NWOu1HgyreT8UtnlFkPcqpo5VuDYVaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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