SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd96e7cd87c537ff61d2c85487944a55fe5c8d882f8df1bd857ff9f9486146c06' 
  AND token = 'di+0GeRK6b6vVgH/s/lfVYHGExqZgMdQe+WLJNWxlvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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