SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e8f23f7ad17326856eae8ad79fb71bdcc65cff6be87451ab7747c310a7d5b17' 
  AND token = 'AIIYzDnzlhnBhDwi9QzLW3chKYi8nhq7K9xTJ30QPcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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