SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ad17f00277987dfcaa138f643fd866962f00700e66deebd1ccb2ef43d9263b6' 
  AND token = '9SHLKWwmQZZIw5ukDKNd/XmBIQ6jGVj6MJXKhlmGArk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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