SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3db4a821a77f1a90424a4489b88ae1c1c7309f72e1ca2e656e81ac7f95638a1d' 
  AND token = 'Pz+8bAnpBXj/K/SpQYdSn/9/yJMHclcVk3qNqSTZdrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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