SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '387c499c66ea04f87ed9cfd69574ae4dc6020d69a849e8e5845efd6a72958667' 
  AND token = 'jF9Fx1DSvNdWln45+rQBDO3UHSLU+TjhkFbu3mBI6tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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