SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '198dcbdec24fc87cf26fb8dc1597fdf811622c6a1783467c17387b6fc9149c52' 
  AND token = 'pND7KwqvB+/zePdFfmH73U+SlbkN5Dkl9oi5Pg4hxZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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