SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3121c0ff0ab61e7fc4bb3fff3c0b9231740902c2ab500f94433ff83f3426cbe6' 
  AND token = 'NxDZDSBGqFTPBbKu3lQBByy22XXnF8NA9HBZBPb4AZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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