SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '254b24d518d58ba9039df8df7f64cf5673d106c480d5e5d2477b81e1513839f9' 
  AND token = '3HMLu+hyuKVLohvVk/Z8jD6gXs/h6Gef2i+55mcv4Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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