SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7cb8d734d1da2b56d6cfcba8c25c407c85f3eb634680c5dc5497fe69e3b2611' 
  AND token = 'xLXw8wfhLsyB9Q6X2Hmfuuplur5LpoRYK9VeqIbpxOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}