SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df2c54aef5d3ca2d00e52355ce0652a10f3337711d779c25f74f532df4cf396' 
  AND token = 'UjY+vPzsLmUOY9yxgfoyCQv9SgoUoUG6urlkEYtDvgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}