SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c5610ce4705825756e18c989177eec32a796949a4903578176a4368c3fd9e93' 
  AND token = '7PBxtUQQPZNYQjEmzee85/udvB0Hi7AilAVBhILX+5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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