SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b0ac07d79957ac82986f357e2b950c9c6e5fbf781a59b640609c50b2fb0c61' 
  AND token = 'DU3AGB+ASnt257MxGMEUer+1mUfbxVh6KJIYgdd6V8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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