SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25638d610890bd2f96d5c6a6828628a51ebd7a0669e0d4842a73bc7281465241' 
  AND token = 's/WpQ/rasqIiWqq+CNj3K+JwhvF9YdRZZbO5FkOLAdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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