SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3bf00ad6f4022376a3984e0764310eb0f32452074d94f09534d7fde79aa9768a' 
  AND token = 'MubhkzdQKBZ7r+adPtJ3664oFD9Dsb2QjsM0yNdoc04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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