SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fbe4dce79e4d58179bea3ee1e702cdbce6e581c22001e61b42f1e74d53096e4' 
  AND token = 'FXig2dzTvb9G2onCkcJfpwyF6lJDH+eStIqf8fYfg8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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