SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c055c1ecb69405a6ae4d8f851df8c8b99dc71ccb5ad5c5b22756bcee354cd3' 
  AND token = 'WMM6/D2/GVY+bhIrY9acwte4DA6Yq6CDk4VIu1CVeGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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