SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7116b6b1f4fea216608815beae7ec78c38fc071cb4e94621a3e763d86c733aa5' 
  AND token = 'nSoiRx2qvlGQgm/BusEHvhhDVf2IgzZLi4nBZTR6GG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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