SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39fca2d75ea675f92b9eedbd3fe7096c9bd11ec7a5796f20f427f05109a543c6' 
  AND token = 'HoAdsukSDzNV/qZvwGBwI1wMjZPpqbOTZy/KDoOayQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}