SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ce5374ba2bebcadd153bd2ba4f7ea8b439b9d7aab23ef2fb096f6091a73f269' 
  AND token = '0946cLVbuG8Rd/7mIfsqojyyegAuTcLL6bEkVb5Mm5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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