SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0f80068847cd8af346029f7feef4020afae88daf26a4f2232aaf399a624f3b4' 
  AND token = 'bJpbxODH0SH6xGf0qPeaVmnY49QknGWpTlp+hxiPOm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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