SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d9946f7f61cad43e001a9d13a038d1ff0f4f003b150cd0606a2e376cd3fabfe' 
  AND token = 'bN54yuVQxStbkfyk4qbFQPfQnOxzXrWSX+Grb/ARJMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}