SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae97c5f9707925d4c214b5900426343e4839242c545d5ad0397fcf92939183b' 
  AND token = 'WBZqUMDj62IpnBAqIxb9omi8GIwNvl3TxiVH1uq/F9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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