SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33dc7c013963c0d484bf86e72f908f0226bcd1c5eae1dcfd2fe608b84244ac36' 
  AND token = 'PwBg2kMsdNJwEEDbyRtvCge1OotOj7Cue2vO+NsxnRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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