SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bce3ed67c7fa08a5a52275aa7cd7248f0768743ce99baab9536ec01bb21a6365' 
  AND token = 'AcDut6VJNklhBQ4Vhf8Z7pgUtv9BPv1rAxNZmuWhr+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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