SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c3605a542ace6d7f9e6a3d703d5647441819c5c397b97c3f1129611baffa831' 
  AND token = '+cGGS4oVjUECq2MlIk/lKzjaOg62ruvKzFhDyBXeX+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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