SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a177b34510e19d98006cf795e7817921bcb9355cce5ac725daf366527ed5a3f5' 
  AND token = 'beuoJXTvDfqMvCSNTQzt4a8yye5Jf1W33bRRtMUZLv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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