SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99f456196a43ff1ea4a0654b9f42a4945e8c57f816f89bd155ab051727f02a7f' 
  AND token = 'nGXYivI1JU3CosAsiVEzkLCNFzZmE2/uGJL6koDUCXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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