SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce16a786477f02cdbcf9edaeea7fc2907f71b731f9abf0ebd8c00a6ddb9743fc' 
  AND token = 'eBWCewhYAjBTK9lRgdPVPj5T1NqxzyjMaLs97RcCG5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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