Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '500f1657929b6062044dfdfe63251274bdc2b1459ba40e79415ae7eb607794a6' 
  AND token = '6sdWWbOQCEhmi5oEPzdxMfjZ9CYZ65oQBmdg1Fbp5n0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}