SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd7d259b714d690d3cb955dbfbf3c388c3e0a2344192c40b2e6b8b529ce1465b' 
  AND token = 'zV1ox+/Jw6Aa/bGV3gOn8DU3FZ8RKFLp58EVFB7d+no=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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