SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fa86711c9035e5a5766bb4333e2edf3683432d7b36a713d9650d9bb9b21b63d' 
  AND token = '7VYGdcvLgRReMyA+yZExfExYQkT3d4lUc+nmczHYx3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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