SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c1389349e1ac9f3bb317cd95f811b04ed9ad819997518ce762172594d7b286' 
  AND token = 'E/O2U3cIoLpan3HuUSi4/eb+wfDDOm1SSQ0YEY8OkgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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