SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69cec09eb2dd3c8999ec5b47b73d61cca71e0f9736126da517c73f455de87973' 
  AND token = 'w20aQH04rRrj6216hgrhpIDqZyxZfhtSKCiqcU3+fCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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