SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e470e7253fb99bd9617d6aa6aed4dc05cefd13c95c405c4605fb1e854ac38807' 
  AND token = 's3idHZWluzApL6GaSW6EwMjaxGV7Jo2mpZLIeSzvMxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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