SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fb097ba70b2f4c4c1b2f5c938f155eedad201aebd9c4505f035523571c762e6' 
  AND token = '0rY8bL+U8LqzPwi9+5GZ/pPLKHO1/UqGLHNcVn/LvgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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