SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c6cca34e04d0c0065bdfb600ab1af24411820d5b6d60a800d15bf9c92a8f31f' 
  AND token = 'yrBsViCUdU9z84w/DytJjvWDqnQMF9voYNGsfBLGB+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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