SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '728c587420ccaff3dd570dae1c253acc0457da110e7c7c8f08f14457a5f92e27' 
  AND token = 'YDxTJbJKQryCMDpWdUJOZdPiwD8IeXIlH73FdrL4rQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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