SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d1140b9a312a507088be3e87d9ae74631d4d06abee2da2d49ce99680a02e182' 
  AND token = 'HDJLVJI+emfdXCQaoAmCpU5XhGwfYFapsWWkeznBpnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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