SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e53dda8f0427568e9803fbc9304f01bafeeb79b39de7c0767e6c388f33b11da' 
  AND token = 'WoaJ5/jfpXxFsow6SIUgqZCvst7BhGqT0RVZPGgfj/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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