SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83145c62b7c06b727998a9324279662d88e0ff722794bb3087602dc46ee41d69' 
  AND token = '4Jq5RCVZDpOlhb1aWkO9aSzHP+qZ5nwGgBkavhTSdZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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