SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f2dcc9314d9a92effad1d33b16fbf0ab585a8fe9e30c73470dd6add175b921' 
  AND token = 'jVDTC0WZ6bsqlVQyMBASs9upbESuiKBmgY7NzfGhl+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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