SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bcb3875b087137f961a43420c89c12a59145629ba98e42aec20c6d57d88c1f3' 
  AND token = 'sMtPNqX01eBOwzhmsRqDGtzxkGanne93xYxPMqyPK40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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