SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62af66035c3c7609baa67ebf8a20b5d9fbd3459bf479d198030b1965365c3d3e' 
  AND token = 'sVLGa1bPLurleAmVfU2TIcxtUz5FnaXl9wz6vErWRkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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