SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78e4b53b4dab89f657eaea6742eaa4b4a239880fa93330a6af79fb624fa91cc7' 
  AND token = 'UEnBPi7RdRle3zbVejLd0SJiZNGUBolgvc/pqiVjU+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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