SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccf9103e2b48d1196773f1e97942b9129dd9f428076a536409ca646ca50d8c52' 
  AND token = 'RV8VRcD9a8jfPMYf4CH4Rfh9ZVeGDqm9BqWy0N/vq/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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