SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9269a966e018e4cf329181e33d282d6afaf43e60c5792ce4a20023c58b98ffde' 
  AND token = 'ad5kt/4g77ISFxxCmjA5+BDwSqve6wkDdx1J5efjs1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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