SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '885f7aaf50b437e4632c9c3ddf226330432ba3b3016b43b71f3a7a7c05ca86da' 
  AND token = 'Gn6PE18lF64srEyXAebHUZRAFaI9TkqVwe9ZSFzOYVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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