SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e56b9f5bf853a087da4b502597a44ec1bf50418cce70e7fe2ddb9689b340e68d' 
  AND token = 'LJsoutpLifoX7u+gfgAUnKRsyiXdsiCHz71FjpgfCsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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