SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de12d8d2b64377c25088e14fa9044f1b1a34f9ef9d8833c378e3b9ce6e0cf773' 
  AND token = 'E8G5WGBgkiOnJPigwUUYD1Z0+DWm87+XOkoolsKDP/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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