SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a9c9dbbbe37df604e68fa8cfbe376ab1781d996d91c1e16b2d1845d7381cd13' 
  AND token = 'j5WKob2TKMEVHzXG6BzySTVJsGn7Ug83zRau44U5U9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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