SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f5373879c904956e101ddff6e11879a6faa484b806aa51b3956b857e9795ed5' 
  AND token = 'HwGIg757dRqKkT9UdnUZiEUJfpeXQuGUIG2RTkEZMuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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