Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f4ce8b308f01b8d9896e36cac0cad51472043f4f0f915d75bd0bf71ee39c97' 
  AND token = 'Eg0BSx24iVEDOCVKQHwn9uch9wr5qy0UnEeIvtF0Tj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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