SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438c75e009ee3caf480f4f3f10b67748d78c63832fbbc301e764b96c65d1365d' 
  AND token = 'tnWzCrVXnPgKC6izY8GSqjHgqRT66E4Cdx/F/ZuSJmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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