SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '081a35f430e6e17fcd5ea140a17bc875b1def6d8c456e272b7ac12f00749b8d1' 
  AND token = 'SPyLl0PTcJVVCAATnkypIaTK2HZCvm9bNKh3xTBYaWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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