SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84db8f59698a8a0e3af5c8ca6f7c76d7fb1432f11cea481f72d596ae6dac90de' 
  AND token = 'e0N3iKyekeR5TkZKXxyXTTi+Hezv77T/LyXHHjfQEcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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