SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91832bc413040fc72924d1d583ece1cbf694b3f622712aab3cd9c401a6dab007' 
  AND token = 'SDwyJHqf17SuS28GXmiaQZQMq/4hKrzqjwoRUueCbYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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