SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4714b34017ef40e5fc4bee3955c08440a2dd48c27ec7efc3f1258beaa260478f' 
  AND token = 'hJ9VvZjAKnSJZZX1Pdpjew8h9xkF/OgddDowJ29DnKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00108

JSON explain

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