SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdcb16f2ad9a3f7db0cc0931ed45851ceb6f6489a22bd83f4bcf129087fb8d01' 
  AND token = 'kNYyHrD/dpDCVDj+2CWii11sd5WIQqUrDzqsuiy1mE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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