SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa8ae5fafdd6dff965b19e636398310d473ddf2b2006701567c73cf297673671' 
  AND token = '2h8BSAx70Z8qJ1hGnr+tIC7D6j1YqFjV4KT5z9EuQqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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