SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93387c6c80c37b7f515619ba8c1005a63776c6b1a9752bd531b3595ea1496895' 
  AND token = 'IJCZlg7+4JxXf08tvUvUGbkoMhFYzlSuJ9FpWCWMlug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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