SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd9d32b7f27caa1d7adbf27e5c90a7d61495c07fd65fabd450e1b292367dca7' 
  AND token = 'djfFKJUaxnsO3wNiNOAsx+dh7xNL4gDCACDUprTcOR8=' 
  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"
    }
  }
}