SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe4cb9a289f35bfec2783722d852b18d4e8877e9751918a6ac127d6f5bb5484a' 
  AND token = 'rQmjcW7/MQILJfXHqScdrLoYP+70hbBmVz0bX0OOGSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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