SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce24653e94a5fbce00b675c0ab462fdf2d9929724538b20f9fd69a38717abf6d' 
  AND token = 'sQLJY6WlRpRVmXs3KDViutU/fCYK6NnY8gLusZT7sJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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