SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88988d6be50d8b13902bfa4bc7e3c59dac06bbfc6310d55de81ed0709847b101' 
  AND token = 'LzVn6T2YFtEC4oXm44YUiHICCaWDfN0DHvJS99hartU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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