SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '161c902e521030c31beaafd62517e135dc48d68a3767fe8777a4a957bfe9fa8b' 
  AND token = 'HUwILI4IrflSdDBjvfKPjs6dhP6pyQCZgugHwfAs1UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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