SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13f04db8ff2daf3f71c480ff1417a90f1f6264cc95dd2a44056c86b9838dff04' 
  AND token = 'iC/UKd+BJ7zJiL6aS7U4+9qTOvpOFjKIgFKujUGs6vU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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