SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813e4a787dcffb5519706ccf96cf7ed5039cd147c0d38b5c665896a0561b172e' 
  AND token = 'dKUpKz9iPGIXAsR48vZp8vCVozpBYvZM6lqc+ZFFI9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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