SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e15ff8264d453b0157c15a4f3d914e0a24660ddce4c82efd244fd219a4d69958' 
  AND token = 'd3QzW2MmmWHanJpjvTDM5VOSpE6LR88+U9HcYNafFTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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