SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5abe54039aadfe1a9ec12bd588e40b5b9b4b00fde899257c400a61337fc65a1' 
  AND token = 'cQVPR108WzAeMzujTZVIf5U1ppyXtkah2eBz7RhshBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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