SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a89170436724415f338029b595e07a23c909aa54729abc39e625c4967165446' 
  AND token = '4rawYaiz4nGoZKPpWSxMNnQZ+HtmjcJiOCRO+BOrtIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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