SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a92e77c45fc597606864a6956bde8e03634f831aea3dc44bcc471c8973f4105' 
  AND token = 'RAZTsK0fswEy/YtrXYzB8rq8lbhWB4vUhRowhFx2ZFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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