Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c646950d784576f8cecc64b78be65a3eecef89e537f0bdc02ddeccde5a22f3e4' 
  AND token = 'dI1Z5twPmP7uspt6OzwpTnzf0Z3yYhKYBMxsRLFcOUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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