SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91614198cf4df00967e653d6efc8dd657c407b5d1826fd9f590e7a9abce355b7' 
  AND token = '8uxUxmHOcqsRsB3QlLBh54gbx/RVI8qK+2ZEh9jDyiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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