SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2fafebb2bf7a663012056a9694ee62466144ca530b11b8ffb28d1e8817ebc86' 
  AND token = '0N7Hqbl2+FUKFqbEimGtmCvVVS6uZKfMW5T1gdNKfEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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