SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae3179402007c3f59548aef11d738e8112447047a13eaa739fc629e8d7b31d5' 
  AND token = 'fvlOUtMlgWw1JtQuagWpObvv1EexxnoXG9I9apvlkxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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