SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b14a92b25ded206714bb2a884bd7d309e978c60969d704fee9bc0cc09feacc9' 
  AND token = 'gJVghMKcCAVxGIAUzoxEgFofEZ94sWY2rPkf3UNT/us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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