SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b6b7c19c304f6420b505fa65ed97c8c037019d290728969ad82a923f3cee910' 
  AND token = 'EZVvT62MfUB1pvS0ywOLKJzqHh1yJ1KiEowCufSJMn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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