SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61247867c214bbf49534b0882060a23d99e27a7bb0ac6827d3d283a162da7488' 
  AND token = '/fFz5amGdgw3V0K2RIbUB7IU1t1qafozxhdpYWacVvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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