SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41b658e130951be9c74cfbf80a7112ab68aaa9422a31ceaa6ac1f15fe2e634d2' 
  AND token = 'tg3IzYdvc1Trps6IT8gQRVAJ6qRqwn1Cod8QkN2oJwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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