SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f080499c43aca3064e1245a75a577b3a39b862586fd0575db0adb4590ae35650' 
  AND token = 'AK9W4oGrdBJSeppJNV7xt0oRbQuOdSMlT+mDoEg2lMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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