SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '863362e5b1752905040f4ca56be22bb47cc731947910914ebbe0639e919a7719' 
  AND token = 'VRFAs65iFY0A2TvlueCravziPdsznnbQGFTwanDy45k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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