SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '935280e2cebc1c646c45b8e0b9d7796558e6f017ae4925c8f5a4a7df284199b3' 
  AND token = 'leZtDN3wh2IwxM2f95HJbmaqZCFmjswglzQoHK6ylAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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