SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd15c943a9b73884b91e2bc1c24c2fe305630b471f585d13110758e237716f858' 
  AND token = '6hAyw+7tWoMsb4KPHjRXwlsfxz1gQLGRadTht8aVHCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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