SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3ba0239078d1efeeca32663fbce5113909e1dd840d194b436bb86a293d806f' 
  AND token = 'AL/OfNoGt3nVLSwloCDvtcTDEn+f/AHoqYI8TFKPNOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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