SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36c65baff8e7dca1153925fb661625ea2d115613c008a7aa1fe7e04bf5262862' 
  AND token = 'jZ/hNiu+m33rDXHW9RWho5zd86t8meh/wqkVpyZx1d0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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