Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de8d11efd86ed67fabc1b806405e13c7446355f187b328d69c02410ea12c81c6' 
  AND token = 'c+xHY4WhwYAxuYHUIcBvrBjwzeSrhK/Uini12jxy5Oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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