SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9f34d04e4474778514521163f475f43efdf384356a079a7ac15bb22f84a1911' 
  AND token = 'nx0TGsC0nqN8iwPzqfwX+7f0Y7XhfHZgoc/nBJ7g6XU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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