SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31fffb5d9e816844571b9472bef45ec09d167aa1ab810b4aa5ca5ac9fcb82239' 
  AND token = 'O1f71NOz+/pDyhleDVHcAEXqcCgbEQLUfzoyoA2mOJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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